#MINSyntax: MIN([DISTINCT] expr) Returns the minimum value of expr. MIN() may take a string argument; in such cases, it returns the minimum string value. See http://dev.mysql.com/doc/refman/5.1/en/mysql-indexes.html. The DISTINCT keyword can be used to find the minimum of the distinct values of expr, however, this produces the same result as omitting DISTINCT. MIN() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html }mysql> SELECT student_name, MIN(test_score), MAX(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html ,"JOINy MySQL supports the following JOIN syntaxes for the table_references part of SELECT statements and multiple-table DELETE and UPDATE statements: table_references: table_reference [, table_reference] ... table_reference: table_factor | join_table table_factor: tbl_name [[AS] alias] [index_hint_list] | table_subquery [AS] alias | ( table_references ) | { OJ table_reference LEFT OUTER JOIN table_reference ON conditional_expr } join_table: table_reference [INNER | CROSS] JOIN table_factor [join_condition] | table_reference STRAIGHT_JOIN table_factor | table_reference STRAIGHT_JOIN table_factor ON conditional_expr | table_reference {LEFT|RIGHT} [OUTER] JOIN table_reference join_condition | table_reference NATURAL [{LEFT|RIGHT} [OUTER]] JOIN table_factor join_condition: ON conditional_expr | USING (column_list) index_hint_list: index_hint [, index_hint] ... index_hint: USE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] ([index_list]) | IGNORE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] (index_list) | FORCE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] (index_list) index_list: index_name [, index_name] ... A table reference is also known as a join expression. The syntax of table_factor is extended in comparison with the SQL Standard. The latter accepts only table_reference, not a list of them inside a pair of parentheses. This is a conservative extension if we consider each comma in a list of table_reference items as equivalent to an inner join. For example: SELECT * FROM t1 LEFT JOIN (t2, t3, t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) is equivalent to: SELECT * FROM t1 LEFT JOIN (t2 CROSS JOIN t3 CROSS JOIN t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) In MySQL, CROSS JOIN is a syntactic equivalent to INNER JOIN (they can replace each other). In standard SQL, they are not equivalent. INNER JOIN is used with an ON clause, CROSS JOIN is used otherwise. In general, parentheses can be ignored in join expressions containing only inner join operations. MySQL also supports nested joins (see http://dev.mysql.com/doc/refman/5.1/en/nested-joins.html). Index hints can be specified to affect how the MySQL optimizer makes use of indexes. For more information, see http://dev.mysql.com/doc/refman/5.1/en/index-hints.html. URL: http://dev.mysql.com/doc/refman/5.1/en/join.html rSELECT left_tbl.* FROM left_tbl LEFT JOIN right_tbl ON left_tbl.id = right_tbl.id WHERE right_tbl.id IS NULL; 0http://dev.mysql.com/doc/refman/5.1/en/join.html"HEX$Syntax: HEX(N_or_S) If N_or_S is a number, returns a string representation of the hexadecimal value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,16). If N_or_S is a string, returns a hexadecimal string representation of N_or_S where each character in N_or_S is converted to two hexadecimal digits. The inverse of this operation is performed by the UNHEX() function. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html }mysql> SELECT HEX(255); -> 'FF' mysql> SELECT 0x616263; -> 'abc' mysql> SELECT HEX('abc'); -> 616263 SELECT SRID(GeomFromText('LineString(1 1,2 2)',101)); +-----------------------------------------------+ | SRID(GeomFromText('LineString(1 1,2 2)',101)) | +-----------------------------------------------+ | 101 | +-----------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions2CURRENT_TIMESTAMPSyntax: CURRENT_TIMESTAMP, CURRENT_TIMESTAMP() CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2SHOW CONTRIBUTORS0Syntax: SHOW CONTRIBUTORS The SHOW CONTRIBUTORS statement displays information about the people who contribute to MySQL source or to causes that MySQL AB supports. For each contributor, it displays Name, Location, and Comment values. URL: http://dev.mysql.com/doc/refman/5.1/en/show-contributors.html =http://dev.mysql.com/doc/refman/5.1/en/show-contributors.htmly2VARIANCE(Syntax: VARIANCE(expr) Returns the population standard variance of expr. This is an extension to standard SQL. The standard SQL function VAR_POP() can be used instead. VARIANCE() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2 DROP SERVER&Syntax: DROP SERVER [ IF EXISTS ] server_name Drops the server definition for the server named server_name. The corresponding row within the mysql.servers table will be deleted. This statement requires the SUPER privilege. Dropping a server for a table does not affect any FEDERATED tables that used this connection information when they were created. See [HELP CREATE SERVER]. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-server.html 7http://dev.mysql.com/doc/refman/5.1/en/drop-server.html:2 SHOW AUTHORSSyntax: SHOW AUTHORS The SHOW AUTHORS statement displays information about the people who work on MySQL. For each author, it displays Name, Location, and Comment values. URL: http://dev.mysql.com/doc/refman/5.1/en/show-authors.html 8http://dev.mysql.com/doc/refman/5.1/en/show-authors.htmlG2 VAR_SAMPSyntax: VAR_SAMP(expr) Returns the sample variance of expr. That is, the denominator is the number of rows minus one. VAR_SAMP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlE" CONCAT$VSyntax: CONCAT(str1,str2,...) Returns the string that results from concatenating the arguments. May have one or more arguments. If all arguments are non-binary strings, the result is a non-binary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent binary string form; if you want to avoid that, you can use an explicit type cast, as in this example: SELECT CONCAT(CAST(int_col AS CHAR), char_col); CONCAT() returns NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT CONCAT('My', 'S', 'QL'); -> 'MySQL' mysql> SELECT CONCAT('My', NULL, 'QL'); -> NULL mysql> SELECT CONCAT(14.3); -> '14.3' SELECT CHARSET(CHAR(0x65)), CHARSET(CHAR(0x65 USING utf8)); +---------------------+--------------------------------+ | CHARSET(CHAR(0x65)) | CHARSET(CHAR(0x65 USING utf8)) | +---------------------+--------------------------------+ | binary | utf8 | +---------------------+--------------------------------+ If USING is given and the result string is illegal for the given character set, a warning is issued. Also, if strict SQL mode is enabled, the result from CHAR() becomes NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html omysql> SELECT CHAR(77,121,83,81,'76'); -> 'MySQL' mysql> SELECT CHAR(77,77.3,'77.3'); -> 'MMM' SHOW CREATE FUNCTION test.hello\G *************************** 1. row *************************** Function: hello sql_mode: Create Function: CREATE FUNCTION `test`.`hello`(s CHAR(20)) » RETURNS CHAR(50) RETURN CONCAT('Hello, ',s,'!') character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci Ahttp://dev.mysql.com/doc/refman/5.1/en/show-create-procedure.html2INTEGERINTEGER[(M)] [UNSIGNED] [ZEROFILL] This type is a synonym for INT. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html2LOWER$OSyntax: LOWER(str) Returns the string str with all characters changed to lowercase according to the current character set mapping. The default is latin1 (cp1252 West European). mysql> SELECT LOWER('QUADRATICALLY'); -> 'quadratically' LOWER() (and UPPER()) are ineffective when applied to binary strings (BINARY, VARBINARY, BLOB). To perform lettercase conversion, convert the string to a non-binary string: mysql> SET @str = BINARY 'New York'; mysql> SELECT LOWER(@str), LOWER(CONVERT(@str USING latin1)); +-------------+-----------------------------------+ | LOWER(@str) | LOWER(CONVERT(@str USING latin1)) | +-------------+-----------------------------------+ | New York | new york | +-------------+-----------------------------------+ URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SHOW COLUMNS FROM City; +------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+----------+------+-----+---------+----------------+ | Id | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | Country | char(3) | NO | UNI | | | | District | char(20) | YES | MUL | | | | Population | int(11) | NO | | 0 | | +------------+----------+------+-----+---------+----------------+ 5 rows in set (0.00 sec) If the data types differ from what you expect them to be based on a CREATE TABLE statement, note that MySQL sometimes changes data types when you create or alter a table. The conditions under which this occurs are described in http://dev.mysql.com/doc/refman/5.1/en/silent-column-changes.html. The FULL keyword causes the output to include the column collation and comments, as well as the privileges you have for each column. You can use db_name.tbl_name as an alternative to the tbl_name FROM db_name syntax. In other words, these two statements are equivalent: mysql> SHOW COLUMNS FROM mytable FROM mydb; mysql> SHOW COLUMNS FROM mydb.mytable; SHOW COLUMNS displays the following values for each table column: Field indicates the column name. Type indicates the column data type. Collation indicates the collation for non-binary string columns, or NULL for other columns. This value is displayed only if you use the FULL keyword. The Null field contains YES if NULL values can be stored in the column, NO if not. The Key field indicates whether the column is indexed: o If Key is empty, the column either is not indexed or is indexed only as a secondary column in a multiple-column, non-unique index. o If Key is PRI, the column is a PRIMARY KEY or is one of the columns in a multiple-column PRIMARY KEY. o If Key is UNI, the column is the first column of a unique-valued index that cannot contain NULL values. o If Key is MUL, multiple occurrences of a given value are allowed within the column. The column is the first column of a non-unique index or a unique-valued index that can contain NULL values. If more than one of the Key values applies to a given column of a table, Key displays the one with the highest priority, in the order PRI, UNI, MUL. A UNIQUE index may be displayed as PRI if it cannot contain NULL values and there is no PRIMARY KEY in the table. A UNIQUE index may display as MUL if several columns form a composite UNIQUE index; although the combination of the columns is unique, each column can still hold multiple occurrences of a given value. The Default field indicates the default value that is assigned to the column. The Extra field contains any additional information that is available about a given column. The value is auto_increment if the column was created with the AUTO_INCREMENT keyword and empty otherwise. Privileges indicates the privileges you have for the column. This value is displayed only if you use the FULL keyword. Comment indicates any comment the column has. This value is displayed only if you use the FULL keyword. SHOW FIELDS is a synonym for SHOW COLUMNS. You can also list a table's columns with the mysqlshow db_name tbl_name command. The DESCRIBE statement provides information similar to SHOW COLUMNS. See [HELP DESCRIBE]. The SHOW CREATE TABLE, SHOW TABLE STATUS, and SHOW INDEX statements also provide information about tables. See [HELP SHOW]. URL: http://dev.mysql.com/doc/refman/5.1/en/show-columns.html 8http://dev.mysql.com/doc/refman/5.1/en/show-columns.html2CREATE TRIGGER&Syntax: CREATE [DEFINER = { user | CURRENT_USER }] TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW trigger_stmt This statement creates a new trigger. A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table. The trigger becomes associated with the table named tbl_name, which must refer to a permanent table. You cannot associate a trigger with a TEMPORARY table or a view. CREATE TRIGGER requires the TRIGGER privilege for the table associated with the trigger. (Before MySQL 5.1.6, this statement requires the SUPER privilege.) The DEFINER clause determines the security context to be used when checking access privileges at trigger activation time. trigger_time is the trigger action time. It can be BEFORE or AFTER to indicate that the trigger activates before or after each row to be modified. trigger_event indicates the kind of statement that activates the trigger. The trigger_event can be one of the following: o INSERT: The trigger is activated whenever a new row is inserted into the table; for example, through INSERT, LOAD DATA, and REPLACE statements. o UPDATE: The trigger is activated whenever a row is modified; for example, through UPDATE statements. o DELETE: The trigger is activated whenever a row is deleted from the table; for example, through DELETE and REPLACE statements. However, DROP TABLE and TRUNCATE statements on the table do not activate this trigger, because they do not use DELETE. Dropping a partition does not activate DELETE triggers, either. See [HELP TRUNCATE TABLE]. URL: http://dev.mysql.com/doc/refman/5.1/en/create-trigger.html :http://dev.mysql.com/doc/refman/5.1/en/create-trigger.html"MONTHSyntax: MONTH(date) Returns the month for date, in the range 1 to 12 for January to December, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero month part. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 0mysql> SELECT MONTH('2008-02-03'); -> 2 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2TINYINTTINYINT[(M)] [UNSIGNED] [ZEROFILL] A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html2 SHOW TRIGGERSUSyntax: SHOW TRIGGERS [FROM db_name] [LIKE 'pattern' | WHERE expr] SHOW TRIGGERS lists the triggers currently defined for tables in a database (the default database unless a FROM clause is given). This statement requires the TRIGGER privilege (prior to MySQL 5.1.22, it requires the SUPER privilege). The LIKE clause, if present, indicates which table names to match and causes the statement to display triggers for those tables. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. For the trigger ins_sum as defined in http://dev.mysql.com/doc/refman/5.1/en/triggers.html, the output of this statement is as shown here: mysql> SHOW TRIGGERS LIKE 'acc%'\G *************************** 1. row *************************** Trigger: ins_sum Event: INSERT Table: account Statement: SET @sum = @sum + NEW.amount Timing: BEFORE Created: NULL sql_mode: Definer: myname@localhost character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci character_set_client is the session value of the character_set_client system variable when the trigger was created. collation_connection is the session value of the collation_connection system variable when the trigger was created. Database Collation is the collation of the database with which the trigger is associated. These columns were added in MySQL 5.1.21. URL: http://dev.mysql.com/doc/refman/5.1/en/show-triggers.html 9http://dev.mysql.com/doc/refman/5.1/en/show-triggers.html.2MASTER_POS_WAITSyntax: MASTER_POS_WAIT(log_name,log_pos[,timeout]) This function is useful for control of master/slave synchronization. It blocks until the slave has read and applied all updates up to the specified position in the master log. The return value is the number of log events the slave had to wait for to advance to the specified position. The function returns NULL if the slave SQL thread is not started, the slave's master information is not initialized, the arguments are incorrect, or an error occurs. It returns -1 if the timeout has been exceeded. If the slave SQL thread stops while MASTER_POS_WAIT() is waiting, the function returns NULL. If the slave is past the specified position, the function returns immediately. If a timeout value is specified, MASTER_POS_WAIT() stops waiting when timeout seconds have elapsed. timeout must be greater than 0; a zero or negative timeout means no timeout. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"REGEXP$qSyntax: expr REGEXP pat, expr RLIKE pat Performs a pattern match of a string expression expr against a pattern pat. The pattern can be an extended regular expression. The syntax for regular expressions is discussed in http://dev.mysql.com/doc/refman/5.1/en/regexp.html. Returns 1 if expr matches pat; otherwise it returns 0. If either expr or pat is NULL, the result is NULL. RLIKE is a synonym for REGEXP, provided for mSQL compatibility. The pattern need not be a literal string. For example, it can be specified as a string expression or table column. *Note*: Because MySQL uses the C escape syntax in strings (for example, "\n" to represent the newline character), you must double any "\" that you use in your REGEXP strings. REGEXP is not case sensitive, except when used with binary strings. URL: http://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html mysql> SELECT 'Monty!' REGEXP 'm%y%%'; -> 0 mysql> SELECT 'Monty!' REGEXP '.*'; -> 1 mysql> SELECT 'new*\n*line' REGEXP 'new\\*.\\*line'; -> 1 mysql> SELECT 'a' REGEXP 'A', 'a' REGEXP BINARY 'A'; -> 1 0 mysql> SELECT 'a' REGEXP '^[a-d]'; -> 1 Ghttp://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html2 IF STATEMENTSyntax: IF search_condition THEN statement_list [ELSEIF search_condition THEN statement_list] ... [ELSE statement_list] END IF IF implements a basic conditional construct. If the search_condition evaluates to true, the corresponding SQL statement list is executed. If no search_condition matches, the statement list in the ELSE clause is executed. Each statement_list consists of one or more statements. *Note*: There is also an IF() function, which differs from the IF statement described here. See http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html. URL: http://dev.mysql.com/doc/refman/5.1/en/if-statement.html 8http://dev.mysql.com/doc/refman/5.1/en/if-statement.html"^YSyntax: ^ Bitwise XOR: URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html gmysql> SELECT 1 ^ 1; -> 0 mysql> SELECT 1 ^ 0; -> 1 mysql> SELECT 11 ^ 3; -> 8 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html2 DROP VIEW&Syntax: DROP VIEW [IF EXISTS] view_name [, view_name] ... [RESTRICT | CASCADE] DROP VIEW removes one or more views. You must have the DROP privilege for each view. If any of the views named in the argument list do not exist, MySQL returns an error indicating by name which non-existing views it was unable to drop, but it also drops all of the views in the list that do exist. The IF EXISTS clause prevents an error from occurring for views that don't exist. When this clause is given, a NOTE is generated for each non-existent view. See [HELP SHOW WARNINGS]. RESTRICT and CASCADE, if given, are parsed and ignored. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-view.html 5http://dev.mysql.com/doc/refman/5.1/en/drop-view.htmlj2WITHINWithin(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially within g2. This tests the opposite relationship as Contains(). URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html " WEEKSyntax: WEEK(date[,mode]) This function returns the week number for date. The two-argument form of WEEK() allows you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the value of the default_week_format system variable is used. See http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT WEEK('2008-02-20'); -> 7 mysql> SELECT WEEK('2008-02-20',0); -> 7 mysql> SELECT WEEK('2008-02-20',1); -> 8 mysql> SELECT WEEK('2008-12-31',1); -> 53 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlV2! SHOW PLUGINSSyntax: SHOW PLUGINS SHOW PLUGINS displays information about known plugins. mysql> SHOW PLUGINS; +------------+--------+----------------+---------+ | Name | Status | Type | Library | +------------+--------+----------------+---------+ | MEMORY | ACTIVE | STORAGE ENGINE | NULL | | MyISAM | ACTIVE | STORAGE ENGINE | NULL | | InnoDB | ACTIVE | STORAGE ENGINE | NULL | | ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | | CSV | ACTIVE | STORAGE ENGINE | NULL | | BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | | FEDERATED | ACTIVE | STORAGE ENGINE | NULL | | MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | +------------+--------+----------------+---------+ URL: http://dev.mysql.com/doc/refman/5.1/en/show-plugins.html 8http://dev.mysql.com/doc/refman/5.1/en/show-plugins.html2"DROP FUNCTION UDFSyntax: DROP FUNCTION function_name This statement drops the user-defined function (UDF) named function_name. To drop a function, you must have the DELETE privilege for the mysql database. This is because DROP FUNCTION removes a row from the mysql.func system table that records the function's name, type, and shared library name. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-function-udf.html =http://dev.mysql.com/doc/refman/5.1/en/drop-function-udf.html,2#PREPARESyntax: PREPARE stmt_name FROM preparable_stmt The PREPARE statement prepares a statement and assigns it a name, stmt_name, by which to refer to the statement later. Statement names are not case sensitive. preparable_stmt is either a string literal or a user variable that contains the text of the statement. The text must represent a single SQL statement, not multiple statements. Within the statement, "?" characters can be used as parameter markers to indicate where data values are to be bound to the query later when you execute it. The "?" characters should not be enclosed within quotes, even if you intend to bind them to string values. Parameter markers can be used only where data values should appear, not for SQL keywords, identifiers, and so forth. If a prepared statement with the given name already exists, it is deallocated implicitly before the new statement is prepared. This means that if the new statement contains an error and cannot be prepared, an error is returned and no statement with the given name exists. The scope of a prepared statement is the client session within which it is created. Other clients cannot see it. URL: http://dev.mysql.com/doc/refman/5.1/en/sql-syntax-prepared-statements.html Jhttp://dev.mysql.com/doc/refman/5.1/en/sql-syntax-prepared-statements.html2$LOCKSyntax: LOCK TABLES tbl_name [[AS] alias] lock_type [, tbl_name [[AS] alias] lock_type] ... lock_type: READ [LOCAL] | [LOW_PRIORITY] WRITE UNLOCK TABLES MySQL enables client sessions to acquire table locks explicitly for the purpose of cooperating with other sessions for access to tables, or to prevent other sessions from modifying tables during periods when a session requires exclusive access to them. A session can acquire or release locks only for itself. One session cannot acquire locks for another session or release locks held by another session. LOCK TABLES acquires table locks for the current thread. It locks base tables or views. (For view locking, LOCK TABLES adds all base tables used in the view to the set of tables to be locked and locks them automatically.) To use LOCK TABLES, you must have the LOCK TABLES privilege, and the SELECT privilege for each object to be locked. MySQL enables client sessions to acquire table locks explicitly Locks may be used to emulate transactions or to get more speed when updating tables. This is explained in more detail later in this section. UNLOCK TABLES explicitly releases any table locks held by the current thread. Another use for UNLOCK TABLES is to release the global read lock acquired with FLUSH TABLES WITH READ LOCK. (You can lock all tables in all databases with a read lock with the FLUSH TABLES WITH READ LOCK statement. See [HELP FLUSH]. This is a very convenient way to get backups if you have a filesystem such as Veritas that can take snapshots in time.) The following discussion applies only to non-TEMPORARY tables. LOCK TABLES is allowed (but ignored) for a TEMPORARY table. The table can be accessed freely by the session within which it was created, regardless of what other locking may be in effect. No lock is necessary because no other session can see the table. The following general rules apply to acquisition and release of locks by a given thread: o Table locks are acquired with LOCK TABLES. o If the LOCK TABLES statement must wait due to locks held by other threads on any of the tables, it blocks until all locks can be acquired. o Table locks are released explicitly with UNLOCK TABLES. o Table locks are released implicitly under these conditions: o LOCK TABLES releases any table locks currently held by the thread before acquiring new locks. o Beginning a transaction (for example, with START TRANSACTION) implicitly performs an UNLOCK TABLES. (Additional information about the interaction between table locking and transactions is given later in this section.) o If a client connection drops, the server releases table locks held by the client. If the client reconnects, the locks will no longer be in effect. In addition, if the client had an active transaction, the server rolls back the transaction upon disconnect, and if reconnect occurs, the new session begins with autocommit enabled. For this reason, clients may wish to disable auto-reconnect. With auto-reconnect in effect, the client is not notified if reconnect occurs but any table locks or current transaction will have been lost. With auto-reconnect disabled, if the connection drops, an error occurs for the next statement issued. The client can detect the error and take appropriate action such as reacquiring the locks or redoing the transaction. See http://dev.mysql.com/doc/refman/5.1/en/auto-reconnect.html. *Note*: If you use ALTER TABLE on a locked table, it may become unlocked. See http://dev.mysql.com/doc/refman/5.1/en/alter-table-problems.html. A table lock protects only against inappropriate reads or writes by other clients. The client holding the lock, even a read lock, can perform table-level operations such as DROP TABLE. Truncate operations are not transaction-safe, so an error occurs if the client attempts one during an active transaction or while holding a table lock. URL: http://dev.mysql.com/doc/refman/5.1/en/lock-tables.html 7http://dev.mysql.com/doc/refman/5.1/en/lock-tables.html"% UPDATEXML$(Syntax: UpdateXML(xml_target, xpath_expr, new_xml) This function replaces a single portion of a given fragment of XML markup xml_target with a new XML fragment new_xml, and then returns the changed XML. The portion of xml_target that is replaced matches an XPath expression xpath_expr supplied by the user. If no expression matching xpath_expr is found, or if multiple matches are found, the function returns the original xml_target XML fragment. All three arguments should be strings. URL: http://dev.mysql.com/doc/refman/5.1/en/xml-functions.html vmysql> SELECT -> UpdateXML('ccc', '/a', 'fff') AS val1, -> UpdateXML('ccc', '/b', 'fff') AS val2, -> UpdateXML('ccc', '//b', 'fff') AS val3, -> UpdateXML('ccc', '/a/d', 'fff') AS val4, -> UpdateXML('ccc', '/a/d', 'fff') AS val5 -> \G *************************** 1. row *************************** val1: fff val2: ccc val3: fff val4: cccfff val5: ccc 9http://dev.mysql.com/doc/refman/5.1/en/xml-functions.html32& RESET SLAVESyntax: RESET SLAVE RESET SLAVE makes the slave forget its replication position in the master's binary logs. This statement is meant to be used for a clean start: It deletes the master.info and relay-log.info files, all the relay logs, and starts a new relay log. *Note*: All relay logs are deleted, even if they have not been completely executed by the slave SQL thread. (This is a condition likely to exist on a replication slave if you have issued a STOP SLAVE statement or if the slave is highly loaded.) Connection information stored in the master.info file is immediately reset using any values specified in the corresponding startup options. This information includes values such as master host, master port, master user, and master password. If the slave SQL thread was in the middle of replicating temporary tables when it was stopped, and RESET SLAVE is issued, these replicated temporary tables are deleted on the slave. URL: http://dev.mysql.com/doc/refman/5.1/en/reset-slave.html 7http://dev.mysql.com/doc/refman/5.1/en/reset-slave.htmlK2'SHOW BINARY LOGSSyntax: SHOW BINARY LOGS SHOW MASTER LOGS Lists the binary log files on the server. This statement is used as part of the procedure described in [HELP PURGE BINARY LOGS], that shows how to determine which logs can be purged. mysql> SHOW BINARY LOGS; +---------------+-----------+ | Log_name | File_size | +---------------+-----------+ | binlog.000015 | 724935 | | binlog.000016 | 733481 | +---------------+-----------+ URL: http://dev.mysql.com/doc/refman/5.1/en/show-binary-logs.html SELECT MINUTE('2008-02-03 10:05:03'); -> 5 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2*DAYSyntax: DAY(date) DAY() is a synonym for DAYOFMONTH(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2+MID$Syntax: MID(str,pos,len) MID(str,pos,len) is a synonym for SUBSTRING(str,pos,len). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT UUID(); -> '6ccd780c-baba-1026-9564-0040f4311e29' Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html2- LINESTRINGTLineString(pt1,pt2,...) Constructs a WKB LineString value from a number of WKB Point arguments. If any argument is not a WKB Point, the return value is NULL. If the number of Point arguments is less than two, the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functionsy2.SLEEP&Syntax: SLEEP(duration) Sleeps (pauses) for the number of seconds given by the duration argument, then returns 0. If SLEEP() is interrupted, it returns 1. The duration may have a fractional part given in microseconds. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"/ CONNECTION_IDSyntax: CONNECTION_ID() Returns the connection ID (thread ID) for the connection. Every connection has an ID that is unique among the set of currently connected clients. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html 0mysql> SELECT CONNECTION_ID(); -> 23786 Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html`20DELETESyntax: Single-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] tbl_name[.*] [, tbl_name[.*]] ... FROM table_references [WHERE where_condition] Or: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name[.*] [, tbl_name[.*]] ... USING table_references [WHERE where_condition] For the single-table syntax, the DELETE statement deletes rows from tbl_name and returns a count of the number of deleted rows. This count can be obtained by calling the ROW_COUNT() function (see http://dev.mysql.com/doc/refman/5.1/en/information-functions.html). The WHERE clause, if given, specifies the conditions that identify which rows to delete. With no WHERE clause, all rows are deleted. If the ORDER BY clause is specified, the rows are deleted in the order that is specified. The LIMIT clause places a limit on the number of rows that can be deleted. For the multiple-table syntax, DELETE deletes from each tbl_name the rows that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be deleted. It is specified as described in http://dev.mysql.com/doc/refman/5.1/en/select.html. Currently, you cannot delete from a table and select from the same table in a subquery. As stated, a DELETE statement with no WHERE clause deletes all rows. A faster way to do this, when you do not need to know the number of deleted rows, is to use TRUNCATE TABLE. However, within a transaction or if you have a lock on the table, TRUNCATE TABLE cannot be used whereas DELETE can. See [HELP TRUNCATE TABLE], and [HELP LOCK]. URL: http://dev.mysql.com/doc/refman/5.1/en/delete.html 2http://dev.mysql.com/doc/refman/5.1/en/delete.html"1ROUNDHSyntax: ROUND(X), ROUND(X,D) Rounds the argument X to D decimal places. The rounding algorithm depends on the data type of X. D defaults to 0 if not specified. D can be negative to cause D digits left of the decimal point of the value X to become zero. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT ROUND(-1.23); -> -1 mysql> SELECT ROUND(-1.58); -> -2 mysql> SELECT ROUND(1.58); -> 2 mysql> SELECT ROUND(1.298, 1); -> 1.3 mysql> SELECT ROUND(1.298, 0); -> 1 mysql> SELECT ROUND(23.298, -1); -> 20 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"2NULLIFSyntax: NULLIF(expr1,expr2) Returns NULL if expr1 = expr2 is true, otherwise returns expr1. This is the same as CASE WHEN expr1 = expr2 THEN NULL ELSE expr1 END. URL: http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html Smysql> SELECT NULLIF(1,1); -> NULL mysql> SELECT NULLIF(1,2); -> 1 Bhttp://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html423CLOSESyntax: CLOSE cursor_name This statement closes a previously opened cursor. If not closed explicitly, a cursor is closed at the end of the compound statement in which it was declared. URL: http://dev.mysql.com/doc/refman/5.1/en/close.html 1http://dev.mysql.com/doc/refman/5.1/en/close.html24 STOP SLAVEaSyntax: STOP SLAVE [thread_type [, thread_type] ... ] thread_type: IO_THREAD | SQL_THREAD Stops the slave threads. STOP SLAVE requires the SUPER privilege. Like START SLAVE, this statement may be used with the IO_THREAD and SQL_THREAD options to name the thread or threads to be stopped. URL: http://dev.mysql.com/doc/refman/5.1/en/stop-slave.html 6http://dev.mysql.com/doc/refman/5.1/en/stop-slave.htmlb"5TIMEDIFFSyntax: TIMEDIFF(expr1,expr2) TIMEDIFF() returns expr1 - expr2 expressed as a time value. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT TIMEDIFF('2000:01:01 00:00:00', -> '2000:01:01 00:00:00.000001'); -> '-00:00:00.000001' mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001', -> '2008-12-30 01:01:01.000002'); -> '46:58:57.999999' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"6REPLACE FUNCTION$Syntax: REPLACE(str,from_str,to_str) Returns the string str with all occurrences of the string from_str replaced by the string to_str. REPLACE() performs a case-sensitive match when searching for from_str. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html Qmysql> SELECT REPLACE('www.mysql.com', 'w', 'Ww'); -> 'WwWwWw.mysql.com' SELECT CASE 1 WHEN 1 THEN 'one' -> WHEN 2 THEN 'two' ELSE 'more' END; -> 'one' mysql> SELECT CASE WHEN 1>0 THEN 'true' ELSE 'false' END; -> 'true' mysql> SELECT CASE BINARY 'B' -> WHEN 'a' THEN 1 WHEN 'b' THEN 2 END; -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.htmlc2:SHOW MASTER STATUSSyntax: SHOW MASTER STATUS Provides status information about the binary log files of the master. Example: mysql> SHOW MASTER STATUS; +---------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +---------------+----------+--------------+------------------+ | mysql-bin.003 | 73 | test | manual,mysql | +---------------+----------+--------------+------------------+ URL: http://dev.mysql.com/doc/refman/5.1/en/show-master-status.html >http://dev.mysql.com/doc/refman/5.1/en/show-master-status.html";ADDTIMESyntax: ADDTIME(expr1,expr2) ADDTIME() adds expr2 to expr1 and returns the result. expr1 is a time or datetime expression, and expr2 is a time expression. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999', '1 1:1:1.000002'); -> '2008-01-02 01:01:01.000001' mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998'); -> '03:00:01.999997' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html:2<SPATIAL!MySQL can create spatial indexes using syntax similar to that for creating regular indexes, but extended with the SPATIAL keyword. Currently, columns in spatial indexes must be declared NOT NULL. The following examples demonstrate how to create spatial indexes: o With CREATE TABLE: CREATE TABLE geom (g GEOMETRY NOT NULL, SPATIAL INDEX(g)); o With ALTER TABLE: ALTER TABLE geom ADD SPATIAL INDEX(g); o With CREATE INDEX: CREATE SPATIAL INDEX sp_index ON geom (g); For MyISAM tables, SPATIAL INDEX creates an R-tree index. For storage engines that support non-spatial indexing of spatial columns, the engine creates a B-tree index. A B-tree index on spatial values will be useful for exact-value lookups, but not for range scans. For more information on indexing spatial columns, see [HELP CREATE INDEX]. To drop spatial indexes, use ALTER TABLE or DROP INDEX: o With ALTER TABLE: ALTER TABLE geom DROP INDEX g; o With DROP INDEX: DROP INDEX sp_index ON geom; Example: Suppose that a table geom contains more than 32,000 geometries, which are stored in the column g of type GEOMETRY. The table also has an AUTO_INCREMENT column fid for storing object ID values. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-indexes.html Dhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-indexes.html"= TIMESTAMPDIFF5Syntax: TIMESTAMPDIFF(unit,datetime_expr1,datetime_expr2) Returns datetime_expr2 - datetime_expr1, where datetime_expr1 and datetime_expr2 are date or datetime expressions. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part '00:00:00' where necessary. The unit for the result (an integer) is given by the unit argument. The legal values for unit are the same as those listed in the description of the TIMESTAMPADD() function. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01'); -> 3 mysql> SELECT TIMESTAMPDIFF(YEAR,'2002-05-01','2001-01-01'); -> -1 mysql> SELECT TIMESTAMPDIFF(MINUTE,'2003-02-01','2003-05-01 12:05:55'); -> 128885 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2>UPPER$Syntax: UPPER(str) Returns the string str with all characters changed to uppercase according to the current character set mapping. The default is latin1 (cp1252 West European). mysql> SELECT UPPER('Hej'); -> 'HEJ' UPPER() is ineffective when applied to binary strings (BINARY, VARBINARY, BLOB). The description of LOWER() shows how to perform lettercase conversion of binary strings. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT FROM_UNIXTIME(1196440219); -> '2007-11-30 10:30:19' mysql> SELECT FROM_UNIXTIME(1196440219) + 0; -> 20071130103019.000000 mysql> SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(), -> '%Y %D %M %h:%i:%s %x'); -> '2007 30th November 10:30:59 2007' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html^2@ MEDIUMBLOB MEDIUMBLOB A BLOB column with a maximum length of 16,777,215 (224 - 1) bytes. Each MEDIUMBLOB value is stored using a three-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html"AIFNULL Syntax: IFNULL(expr1,expr2) If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2. IFNULL() returns a numeric or string value, depending on the context in which it is used. URL: http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html mysql> SELECT IFNULL(1,0); -> 1 mysql> SELECT IFNULL(NULL,10); -> 10 mysql> SELECT IFNULL(1/0,10); -> 10 mysql> SELECT IFNULL(1/0,'yes'); -> 'yes' Bhttp://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html2B SHOW ERRORS5Syntax: SHOW ERRORS [LIMIT [offset,] row_count] SHOW COUNT(*) ERRORS This statement is similar to SHOW WARNINGS, except that instead of displaying errors, warnings, and notes, it displays only errors. The LIMIT clause has the same syntax as for the SELECT statement. See http://dev.mysql.com/doc/refman/5.1/en/select.html. The SHOW COUNT(*) ERRORS statement displays the number of errors. You can also retrieve this number from the error_count variable: SHOW COUNT(*) ERRORS; SELECT @@error_count; URL: http://dev.mysql.com/doc/refman/5.1/en/show-errors.html 7http://dev.mysql.com/doc/refman/5.1/en/show-errors.html"CLEASTSyntax: LEAST(value1,value2,...) With two or more arguments, returns the smallest (minimum-valued) argument. The arguments are compared using the following rules: o If the return value is used in an INTEGER context or all arguments are integer-valued, they are compared as integers. o If the return value is used in a REAL context or all arguments are real-valued, they are compared as reals. o If any argument is a case-sensitive string, the arguments are compared as case-sensitive strings. o In all other cases, the arguments are compared as case-insensitive strings. LEAST() returns NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html mysql> SELECT LEAST(2,0); -> 0 mysql> SELECT LEAST(34.0,3.0,5.0,767.0); -> 3.0 mysql> SELECT LEAST('B','A','C'); -> 'A' @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html\"D=R= Equal: URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html mysql> SELECT 1 = 0; -> 0 mysql> SELECT '0' = 0; -> 1 mysql> SELECT '0.0' = 0; -> 1 mysql> SELECT '0.01' = 0; -> 0 mysql> SELECT '.01' = 0.01; -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"EREVERSE$Syntax: REVERSE(str) Returns the string str with the order of the characters reversed. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html /mysql> SELECT REVERSE('abc'); -> 'cba' "FISNULLSyntax: ISNULL(expr) If expr is NULL, ISNULL() returns 1, otherwise it returns 0. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html Pmysql> SELECT ISNULL(1+1); -> 0 mysql> SELECT ISNULL(1/0); -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.htmlC2GBINARYBINARY(M) The BINARY type is similar to the CHAR type, but stores binary byte strings rather than non-binary character strings. M represents the column length in bytes. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html=2HBLOB DATA TYPEA BLOB is a binary large object that can hold a variable amount of data. The four BLOB types are TINYBLOB, BLOB, MEDIUMBLOB, and LONGBLOB. These differ only in the maximum length of the values they can hold. The four TEXT types are TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT. These correspond to the four BLOB types and have the same maximum lengths and storage requirements. See http://dev.mysql.com/doc/refman/5.1/en/storage-requirements.html. URL: http://dev.mysql.com/doc/refman/5.1/en/blob.html 0http://dev.mysql.com/doc/refman/5.1/en/blob.html\2IBOUNDARY#Boundary(g) Returns a geometry that is the closure of the combinatorial boundary of the geometry value g. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions2J CREATE USER nSyntax: CREATE USER user [IDENTIFIED BY [PASSWORD] 'password'] [, user [IDENTIFIED BY [PASSWORD] 'password']] ... The CREATE USER statement creates new MySQL accounts. To use it, you must have the global CREATE USER privilege or the INSERT privilege for the mysql database. For each account, CREATE USER creates a new row in the mysql.user table that has no privileges. An error occurs if the account already exists. Each account is named using the same format as for the GRANT statement; for example, 'jeffrey'@'localhost'. If you specify only the username part of the account name, a hostname part of '%' is used. For additional information about specifying account names, see [HELP GRANT]. The account can be given a password with the optional IDENTIFIED BY clause. The user value and the password are given the same way as for the GRANT statement. In particular, to specify the password in plain text, omit the PASSWORD keyword. To specify the password as the hashed value as returned by the PASSWORD() function, include the PASSWORD keyword. See [HELP GRANT]. URL: http://dev.mysql.com/doc/refman/5.1/en/create-user.html 7http://dev.mysql.com/doc/refman/5.1/en/create-user.html2KPOINTPoint(x,y) Constructs a WKB Point using its coordinates. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions"L CURRENT_USERSyntax: CURRENT_USER, CURRENT_USER() Returns the username and hostname combination for the MySQL account that the server used to authenticate the current client. This account determines your access privileges. The return value is a string in the utf8 character set. The value of CURRENT_USER() can differ from the value of USER(). URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html mysql> SELECT USER(); -> 'davida@localhost' mysql> SELECT * FROM mysql.user; ERROR 1044: Access denied for user ''@'localhost' to database 'mysql' mysql> SELECT CURRENT_USER(); -> '@localhost' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html2MLCASE$zSyntax: LCASE(str) LCASE() is a synonym for LOWER(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT 0.1 <= 2; -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html'"O SHOW PROFILES Syntax: SHOW PROFILES SHOW PROFILE [type [, type] ... ] [FOR QUERY n] [LIMIT row_count [OFFSET offset]] type: ALL | BLOCK IO | CONTEXT SWITCHES | CPU | IPC | MEMORY | PAGE FAULTS | SOURCE | SWAPS The SHOW PROFILES and SHOW PROFILE statements display profiling information that indicates resource usage for statements executed during the course of the current session. Profiling is controlled by the profiling session variable, which has a default value of 0 (OFF). Profiling is enabled by setting profiling to 1 or ON: mysql> SET profiling = 1; SHOW PROFILES displays a list of the most recent statements sent to the master. The size of the list is controlled by the profiling_history_size session variable, which has a default value of 15. The maximum value is 100. Setting the value to 0 has the practical effect of disabling profiling. All statements are profiled except SHOW PROFILES and SHOW PROFILE, so you will find neither of those statements in the profile list. Malformed statements are profiled. For example, SHOW PROFILING is an illegal statement, and a syntax error occurs if you try to execute it, but it will show up in the profiling list. SHOW PROFILE displays detailed information about a single statement. Without the FOR QUERY n clause, the output pertains to the most recently executed statement. If FOR QUERY n is included, SHOW PROFILE displays information for statement n. The values of n correspond to the Query_ID values displayed by SHOW PROFILES. The LIMIT row_count clause may be given to limit the output to row_count rows. If LIMIT is given, OFFSET offset may be added to begin the output offset rows into the full set of rows. By default, SHOW PROFILE displays Status and Duration columns. The Status values are like the State values displayed by SHOW PROCESSLIST, althought there might be some minor differences in interpretion for the two statements for some status values (see http://dev.mysql.com/doc/refman/5.1/en/thread-information.html). Optional type values may be specified to display specific additional types of information: o ALL displays all information o BLOCK IO displays counts for block input and output operations o CONTEXT SWITCHES displays counts for voluntary and involuntary context switches o CPU displays user and system CPU usage times o IPC displays counts for messages sent and received o MEMORY is not currently implemented o PAGE FAULTS displays counts for major and minor page faults o SOURCE displays the names of functions from the source code, together with the name and line number of the file in which the function occurs o SWAPS displays swap counts Profiling is enabled per session. When a session ends, its profiling information is lost. URL: http://dev.mysql.com/doc/refman/5.1/en/show-profiles.html mysql> SELECT @@profiling; +-------------+ | @@profiling | +-------------+ | 0 | +-------------+ 1 row in set (0.00 sec) mysql> SET profiling = 1; Query OK, 0 rows affected (0.00 sec) mysql> DROP TABLE IF EXISTS t1; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> CREATE TABLE T1 (id INT); Query OK, 0 rows affected (0.01 sec) mysql> SHOW PROFILES; +----------+----------+--------------------------+ | Query_ID | Duration | Query | +----------+----------+--------------------------+ | 0 | 0.000088 | SET PROFILING = 1 | | 1 | 0.000136 | DROP TABLE IF EXISTS t1 | | 2 | 0.011947 | CREATE TABLE t1 (id INT) | +----------+----------+--------------------------+ 3 rows in set (0.00 sec) mysql> SHOW PROFILE; +----------------------+----------+ | Status | Duration | +----------------------+----------+ | checking permissions | 0.000040 | | creating table | 0.000056 | | After create | 0.011363 | | query end | 0.000375 | | freeing items | 0.000089 | | logging slow query | 0.000019 | | cleaning up | 0.000005 | +----------------------+----------+ 7 rows in set (0.00 sec) mysql> SHOW PROFILE FOR QUERY 1; +--------------------+----------+ | Status | Duration | +--------------------+----------+ | query end | 0.000107 | | freeing items | 0.000008 | | logging slow query | 0.000015 | | cleaning up | 0.000006 | +--------------------+----------+ 4 rows in set (0.00 sec) mysql> SHOW PROFILE CPU FOR QUERY 2; +----------------------+----------+----------+------------+ | Status | Duration | CPU_user | CPU_system | +----------------------+----------+----------+------------+ | checking permissions | 0.000040 | 0.000038 | 0.000002 | | creating table | 0.000056 | 0.000028 | 0.000028 | | After create | 0.011363 | 0.000217 | 0.001571 | | query end | 0.000375 | 0.000013 | 0.000028 | | freeing items | 0.000089 | 0.000010 | 0.000014 | | logging slow query | 0.000019 | 0.000009 | 0.000010 | | cleaning up | 0.000005 | 0.000003 | 0.000002 | +----------------------+----------+----------+------------+ 7 rows in set (0.00 sec) 9http://dev.mysql.com/doc/refman/5.1/en/show-profiles.html2PUPDATESyntax: Single-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] tbl_name SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_references SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] For the single-table syntax, the UPDATE statement updates columns of existing rows in tbl_name with new values. The SET clause indicates which columns to modify and the values they should be given. Each value can be given as an expression, or the keyword DEFAULT to set a column explicitly to its default value. The WHERE clause, if given, specifies the conditions that identify which rows to update. With no WHERE clause, all rows are updated. If the ORDER BY clause is specified, the rows are updated in the order that is specified. The LIMIT clause places a limit on the number of rows that can be updated. For the multiple-table syntax, UPDATE updates rows in each table named in table_references that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be updated. It is specified as described in http://dev.mysql.com/doc/refman/5.1/en/select.html. The UPDATE statement supports the following modifiers: o If you use the LOW_PRIORITY keyword, execution of the UPDATE is delayed until no other clients are reading from the table. This affects only storage engines that use only table-level locking (MyISAM, MEMORY, MERGE). o If you use the IGNORE keyword, the update statement does not abort even if errors occur during the update. Rows for which duplicate-key conflicts occur are not updated. Rows for which columns are updated to values that would cause data conversion errors are updated to the closest valid values instead. URL: http://dev.mysql.com/doc/refman/5.1/en/update.html 2http://dev.mysql.com/doc/refman/5.1/en/update.html)"Q IS NOT NULLSyntax: IS NOT NULL Tests whether a value is not NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html Qmysql> SELECT 1 IS NOT NULL, 0 IS NOT NULL, NULL IS NOT NULL; -> 1, 1, 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html2RCASE STATEMENTlSyntax: CASE case_value WHEN when_value THEN statement_list [WHEN when_value THEN statement_list] ... [ELSE statement_list] END CASE Or: CASE WHEN search_condition THEN statement_list [WHEN search_condition THEN statement_list] ... [ELSE statement_list] END CASE The CASE statement for stored programs implements a complex conditional construct. If a search_condition evaluates to true, the corresponding SQL statement list is executed. If no search condition matches, the statement list in the ELSE clause is executed. Each statement_list consists of one or more statements. If no when_value or search_condition matches the value tested and the CASE statement contains no ELSE clause, a Case not found for CASE statement error results. Each statement_list consists of one or more statements; an empty statement_list is not allowed. To handle situations where no value is matched by any WHEN clause, use an ELSE containing an empty BEGIN ... END block, as shown in this example: DELIMITER | CREATE PROCEDURE p() BEGIN DECLARE v INT DEFAULT 1; CASE v WHEN 2 THEN SELECT v; WHEN 3 THEN SELECT 0; ELSE BEGIN END; END CASE; END; | (The indentation used here in the ELSE clause is for purposes of clarity only, and is not otherwise significant.) *Note*: The syntax of the CASE statement used inside stored programs differs slightly from that of the SQL CASE expression described in http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html. The CASE statement cannot have an ELSE NULL clause, and it is terminated with END CASE instead of END. URL: http://dev.mysql.com/doc/refman/5.1/en/case-statement.html :http://dev.mysql.com/doc/refman/5.1/en/case-statement.htmlZ2SEXECUTE STATEMENTSyntax: EXECUTE stmt_name [USING @var_name [, @var_name] ...] After preparing a statement, you execute it with an EXECUTE statement that refers to the prepared statement name. If the prepared statement contains any parameter markers, you must supply a USING clause that lists user variables containing the values to be bound to the parameters. Parameter values can be supplied only by user variables, and the USING clause must name exactly as many variables as the number of parameter markers in the statement. You can execute a given prepared statement multiple times, passing different variables to it or setting the variables to different values before each execution. URL: http://dev.mysql.com/doc/refman/5.1/en/sql-syntax-prepared-statements.html Jhttp://dev.mysql.com/doc/refman/5.1/en/sql-syntax-prepared-statements.htmlj2T DROP INDEX&Syntax: DROP [ONLINE|OFFLINE] INDEX index_name ON tbl_name DROP INDEX drops the index named index_name from the table tbl_name. This statement is mapped to an ALTER TABLE statement to drop the index. See [HELP ALTER TABLE]. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-index.html 6http://dev.mysql.com/doc/refman/5.1/en/drop-index.html "U MATCH AGAINST$ Syntax: MATCH (col1,col2,...) AGAINST (expr [search_modifier]) MySQL has support for full-text indexing and searching: o A full-text index in MySQL is an index of type FULLTEXT. o Full-text indexes can be used only with MyISAM tables, and can be created only for CHAR, VARCHAR, or TEXT columns. o A FULLTEXT index definition can be given in the CREATE TABLE statement when a table is created, or added later using ALTER TABLE or CREATE INDEX. o For large data sets, it is much faster to load your data into a table that has no FULLTEXT index and then create the index after that, than to load data into a table that has an existing FULLTEXT index. Full-text searching is performed using MATCH() ... AGAINST syntax. MATCH() takes a comma-separated list that names the columns to be searched. AGAINST takes a string to search for, and an optional modifier that indicates what type of search to perform. The search string must be a literal string, not a variable or a column name. There are three types of full-text searches: o A boolean search interprets the search string using the rules of a special query language. The string contains the words to search for. It can also contain operators that specify requirements such that a word must be present or absent in matching rows, or that it should be weighted higher or lower than usual. Common words such as "some" or "then" are stopwords and do not match if present in the search string. The IN BOOLEAN MODE modifier specifies a boolean search. For more information, see http://dev.mysql.com/doc/refman/5.1/en/fulltext-boolean.html. o A natural language search interprets the search string as a phrase in natural human language (a phrase in free text). There are no special operators. The stopword list applies. In addition, words that are present in 50% or more of the rows are considered common and do not match. Full-text searches are natural language searches if the IN NATURAL LANGUAGE MODE modifier is given or if no modifier is given. o A query expansion search is a modification of a natural language search. The search string is used to perform a natural language search. Then words from the most relevant rows returned by the search are added to the search string and the search is done again. The query returns the rows from the second search. The IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION or WITH QUERY EXPANSION modifier specifies a query expansion search. For more information, see http://dev.mysql.com/doc/refman/5.1/en/fulltext-query-expansion.html. The IN NATURAL LANGUAGE MODE and IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION modifiers were added in MySQL 5.1.7. URL: http://dev.mysql.com/doc/refman/5.1/en/fulltext-search.html mysql> SELECT id, body, MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root' -> IN NATURAL LANGUAGE MODE) AS score -> FROM articles WHERE MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root' -> IN NATURAL LANGUAGE MODE); +----+-------------------------------------+-----------------+ | id | body | score | +----+-------------------------------------+-----------------+ | 4 | 1. Never run mysqld as root. 2. ... | 1.5219271183014 | | 6 | When configured properly, MySQL ... | 1.3114095926285 | +----+-------------------------------------+-----------------+ 2 rows in set (0.00 sec) ;http://dev.mysql.com/doc/refman/5.1/en/fulltext-search.html2V CREATE EVENT&Syntax: CREATE [DEFINER = { user | CURRENT_USER }] EVENT [IF NOT EXISTS] event_name ON SCHEDULE schedule [ON COMPLETION [NOT] PRESERVE] [ENABLE | DISABLE | DISABLE ON SLAVE] [COMMENT 'comment'] DO sql_statement; schedule: AT timestamp [+ INTERVAL interval] ... | EVERY interval [STARTS timestamp [+ INTERVAL interval] ...] [ENDS timestamp [+ INTERVAL interval] ...] interval: quantity {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE | WEEK | SECOND | YEAR_MONTH | DAY_HOUR | DAY_MINUTE | DAY_SECOND | HOUR_MINUTE | HOUR_SECOND | MINUTE_SECOND} This statement creates and schedules a new event. The minimum requirements for a valid CREATE EVENT statement are as follows: o The keywords CREATE EVENT plus an event name, which uniquely identifies the event in the current schema. (Prior to MySQL 5.1.12, the event name needed to be unique only among events created by the same user on a given database.) o An ON SCHEDULE clause, which determines when and how often the event executes. o A DO clause, which contains the SQL statement to be executed by an event. This is an example of a minimal CREATE EVENT statement: CREATE EVENT myevent ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 HOUR DO UPDATE myschema.mytable SET mycol = mycol + 1; The previous statement creates an event named myevent. This event executes once --- one hour following its creation --- by running an SQL statement that increments the value of the myschema.mytable table's mycol column by 1. The event_name must be a valid MySQL identifier with a maximum length of 64 characters. It may be delimited using back ticks, and may be qualified with the name of a database schema. An event is associated with both a MySQL user (the definer) and a schema, and its name must be unique among names of events within that schema. In general, the rules governing event names are the same as those for names of stored routines. See http://dev.mysql.com/doc/refman/5.1/en/identifiers.html. If no schema is indicated as part of event_name, the default (current) schema is assumed. URL: http://dev.mysql.com/doc/refman/5.1/en/create-event.html 8http://dev.mysql.com/doc/refman/5.1/en/create-event.html"WABS{Syntax: ABS(X) Returns the absolute value of X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Imysql> SELECT ABS(2); -> 2 mysql> SELECT ABS(-32); -> 32 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html?2X POLYFROMWKB PolyFromWKB(wkb[,srid]), PolygonFromWKB(wkb[,srid]) Constructs a POLYGON value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions2YNOT LIKE$Syntax: expr NOT LIKE pat [ESCAPE 'escape_char'] This is the same as NOT (expr LIKE pat [ESCAPE 'escape_char']). URL: http://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html Ghttp://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html"ZSPACE$Syntax: SPACE(N) Returns a string consisting of N space characters. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html ,mysql> SELECT SPACE(6); -> ' ' http://dev.mysql.com/doc/refman/5.1/en/gis-class-geometry.html2\GEOMETRYCOLLECTION GeometryCollection(g1,g2,...) Constructs a WKB GeometryCollection. If any argument is not a well-formed WKB representation of a geometry, the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions"]MAXSyntax: MAX([DISTINCT] expr) Returns the maximum value of expr. MAX() may take a string argument; in such cases, it returns the maximum string value. See http://dev.mysql.com/doc/refman/5.1/en/mysql-indexes.html. The DISTINCT keyword can be used to find the maximum of the distinct values of expr, however, this produces the same result as omitting DISTINCT. MAX() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html }mysql> SELECT student_name, MIN(test_score), MAX(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2^CREATE FUNCTION UDFSyntax: CREATE [AGGREGATE] FUNCTION function_name RETURNS {STRING|INTEGER|REAL|DECIMAL} SONAME shared_library_name A user-defined function (UDF) is a way to extend MySQL with a new function that works like a native (built-in) MySQL function such as ABS() or CONCAT(). function_name is the name that should be used in SQL statements to invoke the function. The RETURNS clause indicates the type of the function's return value. DECIMAL is a legal value after RETURNS, but currently DECIMAL functions return string values and should be written like STRING functions. shared_library_name is the basename of the shared object file that contains the code that implements the function. The file must be located in the plugin directory. This directory is given by the value of the plugin_dir system variable. *Note*: This is a change in MySQL 5.1. For earlier versions of MySQL, the shared object can be located in any directory that is searched by your system's dynamic linker. To create a function, you must have the INSERT privilege for the mysql database. This is necessary because CREATE FUNCTION adds a row to the mysql.func system table that records the function's name, type, and shared library name. If you do not have this table, you should run the mysql_upgrade command to create it. See http://dev.mysql.com/doc/refman/5.1/en/mysql-upgrade.html. URL: http://dev.mysql.com/doc/refman/5.1/en/create-function-udf.html ?http://dev.mysql.com/doc/refman/5.1/en/create-function-udf.htmlv"_*cSyntax: * Multiplication: URL: http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html mysql> SELECT 3*5; -> 15 mysql> SELECT 18014398509481984*18014398509481984.0; -> 324518553658426726783156020576256.0 mysql> SELECT 18014398509481984*18014398509481984; -> 0 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html2` TIMESTAMPETIMESTAMP A timestamp. The range is '1970-01-01 00:00:01' UTC to '2038-01-09 03:14:07' UTC. TIMESTAMP values are stored as the number of seconds since the epoch ('1970-01-01 00:00:00' UTC). A TIMESTAMP cannot represent the value '1970-01-01 00:00:00' because that is equivalent to 0 seconds from the epoch and the value 0 is reserved for representing '0000-00-00 00:00:00', the "zero" TIMESTAMP value. A TIMESTAMP column is useful for recording the date and time of an INSERT or UPDATE operation. By default, the first TIMESTAMP column in a table is automatically set to the date and time of the most recent operation if you do not assign it a value yourself. You can also set any TIMESTAMP column to the current date and time by assigning it a NULL value. Variations on automatic initialization and update properties are described in http://dev.mysql.com/doc/refman/5.1/en/timestamp.html. A TIMESTAMP value is returned as a string in the format 'YYYY-MM-DD HH:MM:SS' with a display width fixed at 19 characters. To obtain the value as a number, you should add +0 to the timestamp column. *Note*: The TIMESTAMP format that was used prior to MySQL 4.1 is not supported in MySQL 5.1; see MySQL 3.23, 4.0, 4.1 Reference Manual for information regarding the old format. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html2a DES_DECRYPT Syntax: DES_DECRYPT(crypt_str[,key_str]) Decrypts a string encrypted with DES_ENCRYPT(). If an error occurs, this function returns NULL. This function works only if MySQL has been configured with SSL support. See http://dev.mysql.com/doc/refman/5.1/en/secure-connections.html. If no key_str argument is given, DES_DECRYPT() examines the first byte of the encrypted string to determine the DES key number that was used to encrypt the original string, and then reads the key from the DES key file to decrypt the message. For this to work, the user must have the SUPER privilege. The key file can be specified with the --des-key-file server option. If you pass this function a key_str argument, that string is used as the key for decrypting the message. If the crypt_str argument does not appear to be an encrypted string, MySQL returns the given crypt_str. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html2b CACHE INDEX]Syntax: CACHE INDEX tbl_index_list [, tbl_index_list] ... IN key_cache_name tbl_index_list: tbl_name [[INDEX|KEY] (index_name[, index_name] ...)] The CACHE INDEX statement assigns table indexes to a specific key cache. It is used only for MyISAM tables. The following statement assigns indexes from the tables t1, t2, and t3 to the key cache named hot_cache: mysql> CACHE INDEX t1, t2, t3 IN hot_cache; +---------+--------------------+----------+----------+ | Table | Op | Msg_type | Msg_text | +---------+--------------------+----------+----------+ | test.t1 | assign_to_keycache | status | OK | | test.t2 | assign_to_keycache | status | OK | | test.t3 | assign_to_keycache | status | OK | +---------+--------------------+----------+----------+ URL: http://dev.mysql.com/doc/refman/5.1/en/cache-index.html 7http://dev.mysql.com/doc/refman/5.1/en/cache-index.html_"cENDPOINT EndPoint(ls) Returns the Point that is the endpoint of the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions 'mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(EndPoint(GeomFromText(@ls))); +-------------------------------------+ | AsText(EndPoint(GeomFromText(@ls))) | +-------------------------------------+ | POINT(3 3) | +-------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions"dCOMPRESS rSyntax: COMPRESS(string_to_compress) Compresses a string and returns the result as a binary string. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. The compressed string can be uncompressed with UNCOMPRESS(). URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html mysql> SELECT LENGTH(COMPRESS(REPEAT('a',1000))); -> 21 mysql> SELECT LENGTH(COMPRESS('')); -> 0 mysql> SELECT LENGTH(COMPRESS('a')); -> 13 mysql> SELECT LENGTH(COMPRESS(REPEAT('a',16))); -> 15 @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html$2eINSERTSyntax: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] {VALUES | VALUE} ({expr | DEFAULT},...),(...),... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name SET col_name={expr | DEFAULT}, ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] SELECT ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] INSERT inserts new rows into an existing table. The INSERT ... VALUES and INSERT ... SET forms of the statement insert rows based on explicitly specified values. The INSERT ... SELECT form inserts rows selected from another table or tables. INSERT ... SELECT is discussed further in [HELP INSERT SELECT]. URL: http://dev.mysql.com/doc/refman/5.1/en/insert.html 2http://dev.mysql.com/doc/refman/5.1/en/insert.html"fCOUNTSyntax: COUNT(expr) Returns a count of the number of non-NULL values of expr in the rows retrieved by a SELECT statement. The result is a BIGINT value. COUNT() returns 0 if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html mysql> SELECT student.student_name,COUNT(*) -> FROM student,course -> WHERE student.student_id=course.student_id -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlt2gHANDLER/Syntax: HANDLER tbl_name OPEN [ [AS] alias] HANDLER tbl_name READ index_name { = | >= | <= | < } (value1,value2,...) [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name READ index_name { FIRST | NEXT | PREV | LAST } [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name READ { FIRST | NEXT } [ WHERE where_condition ] [LIMIT ... ] HANDLER tbl_name CLOSE The HANDLER statement provides direct access to table storage engine interfaces. It is available for MyISAM and InnoDB tables. URL: http://dev.mysql.com/doc/refman/5.1/en/handler.html 3http://dev.mysql.com/doc/refman/5.1/en/handler.htmlT2h MLINEFROMTEXTMLineFromText(wkt[,srid]), MultiLineStringFromText(wkt[,srid]) Constructs a MULTILINESTRING value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions]2iGEOMCOLLFROMWKB GeomCollFromWKB(wkb[,srid]), GeometryCollectionFromWKB(wkb[,srid]) Constructs a GEOMETRYCOLLECTION value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions"j RENAME TABLE&DSyntax: RENAME TABLE tbl_name TO new_tbl_name [, tbl_name2 TO new_tbl_name2] ... This statement renames one or more tables. The rename operation is done atomically, which means that no other thread can access any of the tables while the rename is running. For example, if you have an existing table old_table, you can create another table new_table that has the same structure but is empty, and then replace the existing table with the empty one as follows (assuming that backup_table does not already exist): URL: http://dev.mysql.com/doc/refman/5.1/en/rename-table.html ^CREATE TABLE new_table (...); RENAME TABLE old_table TO backup_table, new_table TO old_table; 8http://dev.mysql.com/doc/refman/5.1/en/rename-table.html2kBOOLEANlBOOL, BOOLEAN These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true: mysql> SELECT IF(0, 'true', 'false'); +------------------------+ | IF(0, 'true', 'false') | +------------------------+ | false | +------------------------+ mysql> SELECT IF(1, 'true', 'false'); +------------------------+ | IF(1, 'true', 'false') | +------------------------+ | true | +------------------------+ mysql> SELECT IF(2, 'true', 'false'); +------------------------+ | IF(2, 'true', 'false') | +------------------------+ | true | +------------------------+ However, the values TRUE and FALSE are merely aliases for 1 and 0, respectively, as shown here: mysql> SELECT IF(0 = FALSE, 'true', 'false'); +--------------------------------+ | IF(0 = FALSE, 'true', 'false') | +--------------------------------+ | true | +--------------------------------+ mysql> SELECT IF(1 = TRUE, 'true', 'false'); +-------------------------------+ | IF(1 = TRUE, 'true', 'false') | +-------------------------------+ | true | +-------------------------------+ mysql> SELECT IF(2 = TRUE, 'true', 'false'); +-------------------------------+ | IF(2 = TRUE, 'true', 'false') | +-------------------------------+ | false | +-------------------------------+ mysql> SELECT IF(2 = FALSE, 'true', 'false'); +--------------------------------+ | IF(2 = FALSE, 'true', 'false') | +--------------------------------+ | false | +--------------------------------+ The last two statements display the results shown because 2 is equal to neither 1 nor 0. We intend to implement full boolean type handling, in accordance with standard SQL, in a future MySQL release. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.htmlU"lDEFAULTSyntax: DEFAULT(col_name) Returns the default value for a table column. An error results if the column has no default value. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html 5mysql> UPDATE t SET i = DEFAULT(i)+1 WHERE id < 100; Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"mMODSyntax: MOD(N,M), N % M, N MOD M Modulo operation. Returns the remainder of N divided by M. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT MOD(234, 10); -> 4 mysql> SELECT 253 % 7; -> 1 mysql> SELECT MOD(29,9); -> 2 mysql> SELECT 29 MOD 9; -> 2 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2nTINYTEXTTINYTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 255 (28 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each TINYTEXT value is stored using a one-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html]2oOPTIMIZE TABLE Syntax: OPTIMIZE [LOCAL | NO_WRITE_TO_BINLOG] TABLE tbl_name [, tbl_name] ... OPTIMIZE TABLE should be used if you have deleted a large part of a table or if you have made many changes to a table with variable-length rows (tables that have VARCHAR, VARBINARY, BLOB, or TEXT columns). Deleted rows are maintained in a linked list and subsequent INSERT operations reuse old row positions. You can use OPTIMIZE TABLE to reclaim the unused space and to defragment the data file. This statement requires SELECT and INSERT privileges for the table. OPTIMIZE TABLE is not supported for partitioned tables. See http://dev.mysql.com/doc/refman/5.1/en/partitioning-maintenance.html, for information about alternatives. URL: http://dev.mysql.com/doc/refman/5.1/en/optimize-table.html :http://dev.mysql.com/doc/refman/5.1/en/optimize-table.html:2pDECODE Syntax: DECODE(crypt_str,pass_str) Decrypts the encrypted string crypt_str using pass_str as the password. crypt_str should be a string returned from ENCODE(). URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html"q<=>Syntax: <=> NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operands are NULL, and 0 rather than NULL if one operand is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html mysql> SELECT 1 <=> 1, NULL <=> NULL, 1 <=> NULL; -> 1, 1, 0 mysql> SELECT 1 = 1, NULL = NULL, 1 = NULL; -> 1, NULL, NULL @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html 2rLOAD DATA FROM MASTER: Syntax: LOAD DATA FROM MASTER This feature is deprecated. We recommend not using it anymore. It is subject to removal in a future version of MySQL. Since the current implementation of LOAD DATA FROM MASTER and LOAD TABLE FROM MASTER is very limited, these statements are deprecated in versions 4.1 of MySQL and above. We will introduce a more advanced technique (called "online backup") in a future version. That technique will have the additional advantage of working with more storage engines. For MySQL 5.1 and earlier, the recommended alternative solution to using LOAD DATA FROM MASTER or LOAD TABLE FROM MASTER is using mysqldump or mysqlhotcopy. The latter requires Perl and two Perl modules (DBI and DBD:mysql) and works for MyISAM and ARCHIVE tables only. With mysqldump, you can create SQL dumps on the master and pipe (or copy) these to a mysql client on the slave. This has the advantage of working for all storage engines, but can be quite slow, since it works using SELECT. This statement takes a snapshot of the master and copies it to the slave. It updates the values of MASTER_LOG_FILE and MASTER_LOG_POS so that the slave starts replicating from the correct position. Any table and database exclusion rules specified with the --replicate-*-do-* and --replicate-*-ignore-* options are honored. --replicate-rewrite-db is not taken into account because a user could use this option to set up a non-unique mapping such as --replicate-rewrite-db="db1->db3" and --replicate-rewrite-db="db2->db3", which would confuse the slave when loading tables from the master. Use of this statement is subject to the following conditions: o It works only for MyISAM tables. Attempting to load a non-MyISAM table results in the following error: ERROR 1189 (08S01): Net error reading from master o It acquires a global read lock on the master while taking the snapshot, which prevents updates on the master during the load operation. If you are loading large tables, you might have to increase the values of net_read_timeout and net_write_timeout on both the master and slave servers. See http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html. Note that LOAD DATA FROM MASTER does not copy any tables from the mysql database. This makes it easy to have different users and privileges on the master and the slave. To use LOAD DATA FROM MASTER, the replication account that is used to connect to the master must have the RELOAD and SUPER privileges on the master and the SELECT privilege for all master tables you want to load. All master tables for which the user does not have the SELECT privilege are ignored by LOAD DATA FROM MASTER. This is because the master hides them from the user: LOAD DATA FROM MASTER calls SHOW DATABASES to know the master databases to load, but SHOW DATABASES returns only databases for which the user has some privilege. See [HELP SHOW DATABASES]. On the slave side, the user that issues LOAD DATA FROM MASTER must have privileges for dropping and creating the databases and tables that are copied. URL: http://dev.mysql.com/doc/refman/5.1/en/load-data-from-master.html Ahttp://dev.mysql.com/doc/refman/5.1/en/load-data-from-master.htmly2sRESET8Syntax: RESET reset_option [, reset_option] ... The RESET statement is used to clear the state of various server operations. You must have the RELOAD privilege to execute RESET. RESET acts as a stronger version of the FLUSH statement. See [HELP FLUSH]. URL: http://dev.mysql.com/doc/refman/5.1/en/reset.html 1http://dev.mysql.com/doc/refman/5.1/en/reset.htmlG2tHELP STATEMENTSyntax: HELP 'search_string' The HELP statement returns online information from the MySQL Reference manual. Its proper operation requires that the help tables in the mysql database be initialized with help topic information (see http://dev.mysql.com/doc/refman/5.1/en/server-side-help-support.html). The HELP statement searches the help tables for the given search string and displays the result of the search. The search string is not case sensitive. URL: http://dev.mysql.com/doc/refman/5.1/en/help.html 0http://dev.mysql.com/doc/refman/5.1/en/help.htmlk"uGET_LOCKSyntax: GET_LOCK(str,timeout) Tries to obtain a lock with a name given by the string str, using a timeout of timeout seconds. Returns 1 if the lock was obtained successfully, 0 if the attempt timed out (for example, because another client has previously locked the name), or NULL if an error occurred (such as running out of memory or the thread was killed with mysqladmin kill). If you have a lock obtained with GET_LOCK(), it is released when you execute RELEASE_LOCK(), execute a new GET_LOCK(), or your connection terminates (either normally or abnormally). Locks obtained with GET_LOCK() do not interact with transactions. That is, committing a transaction does not release any such locks obtained during the transaction. This function can be used to implement application locks or to simulate record locks. Names are locked on a server-wide basis. If a name has been locked by one client, GET_LOCK() blocks any request by another client for a lock with the same name. This allows clients that agree on a given lock name to use the name to perform cooperative advisory locking. But be aware that it also allows a client that is not among the set of cooperating clients to lock a name, either inadvertently or deliberately, and thus prevent any of the cooperating clients from locking that name. One way to reduce the likelihood of this is to use lock names that are database-specific or application-specific. For example, use lock names of the form db_name.str or app_name.str. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html mysql> SELECT GET_LOCK('lock1',10); -> 1 mysql> SELECT IS_FREE_LOCK('lock2'); -> 1 mysql> SELECT GET_LOCK('lock2',10); -> 1 mysql> SELECT RELEASE_LOCK('lock2'); -> 1 mysql> SELECT RELEASE_LOCK('lock1'); -> NULL Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html2vUCASE$zSyntax: UCASE(str) UCASE() is a synonym for UPPER(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html http://dev.mysql.com/doc/refman/5.1/en/show-binlog-events.htmlK2x MPOLYFROMWKB MPolyFromWKB(wkb[,srid]), MultiPolygonFromWKB(wkb[,srid]) Constructs a MULTIPOLYGON value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions"yITERATESyntax: ITERATE label ITERATE can appear only within LOOP, REPEAT, and WHILE statements. ITERATE means "do the loop again." URL: http://dev.mysql.com/doc/refman/5.1/en/iterate-statement.html CREATE PROCEDURE doiterate(p1 INT) BEGIN label1: LOOP SET p1 = p1 + 1; IF p1 < 10 THEN ITERATE label1; END IF; LEAVE label1; END LOOP label1; SET @x = p1; END =http://dev.mysql.com/doc/refman/5.1/en/iterate-statement.html2zDOxSyntax: DO expr [, expr] ... DO executes the expressions but does not return any results. In most respects, DO is shorthand for SELECT expr, ..., but has the advantage that it is slightly faster when you do not care about the result. DO is useful primarily with functions that have side effects, such as RELEASE_LOCK(). URL: http://dev.mysql.com/doc/refman/5.1/en/do.html .http://dev.mysql.com/doc/refman/5.1/en/do.html"{CURTIME$Syntax: CURTIME() Returns the current time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html emysql> SELECT CURTIME(); -> '23:50:26' mysql> SELECT CURTIME() + 0; -> 235026.000000 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2| CHAR_LENGTH$ISyntax: CHAR_LENGTH(str) Returns the length of the string str, measured in characters. A multi-byte character counts as a single character. This means that for a string containing five two-byte characters, LENGTH() returns 10, whereas CHAR_LENGTH() returns 5. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html 2~SETSyntax: SET variable_assignment [, variable_assignment] ... variable_assignment: user_var_name = expr | [GLOBAL | SESSION] system_var_name = expr | [@@global. | @@session. | @@]system_var_name = expr The SET statement assigns values to different types of variables that affect the operation of the server or your client. Older versions of MySQL employed SET OPTION, but this syntax is deprecated in favor of SET without OPTION. URL: http://dev.mysql.com/doc/refman/5.1/en/set-option.html 6http://dev.mysql.com/doc/refman/5.1/en/set-option.html^"CONV?Syntax: CONV(N,from_base,to_base) Converts numbers between different number bases. Returns a string representation of the number N, converted from base from_base to base to_base. Returns NULL if any argument is NULL. The argument N is interpreted as an integer, but may be specified as an integer or a string. The minimum base is 2 and the maximum base is 36. If to_base is a negative number, N is regarded as a signed number. Otherwise, N is treated as unsigned. CONV() works with 64-bit precision. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT CONV('a',16,2); -> '1010' mysql> SELECT CONV('6E',18,8); -> '172' mysql> SELECT CONV(-17,10,-18); -> '-H' mysql> SELECT CONV(10+'10'+'10'+0xa,10,10); -> '40' Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmll2DATEDATE A date. The supported range is '1000-01-01' to '9999-12-31'. MySQL displays DATE values in 'YYYY-MM-DD' format, but allows assignment of values to DATE columns using either strings or numbers. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html2SHOW OPEN TABLESSyntax: SHOW OPEN TABLES [FROM db_name] [LIKE 'pattern' | WHERE expr] SHOW OPEN TABLES lists the non-TEMPORARY tables that are currently open in the table cache. See http://dev.mysql.com/doc/refman/5.1/en/table-cache.html. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. The FROM and LIKE clauses may be used beginning with MySQL 5.1.24. The LIKE clause, if present, indicates which table names to match. The FROM clause, if present, restricts the tables shown to those present in the db_name database. URL: http://dev.mysql.com/doc/refman/5.1/en/show-open-tables.html SELECT EXTRACT(YEAR FROM '2009-07-02'); -> 2009 mysql> SELECT EXTRACT(YEAR_MONTH FROM '2009-07-02 01:02:03'); -> 200907 mysql> SELECT EXTRACT(DAY_MINUTE FROM '2009-07-02 01:02:03'); -> 20102 mysql> SELECT EXTRACT(MICROSECOND -> FROM '2003-01-02 10:30:00.000123'); -> 123 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"ENCRYPT +Syntax: ENCRYPT(str[,salt]) Encrypts str using the Unix crypt() system call and returns a binary string. The salt argument should be a string with at least two characters. If no salt argument is given, a random value is used. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html ;mysql> SELECT ENCRYPT('hello'); -> 'VxuFAJXVARROc' @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html2 SHOW STATUSSyntax: SHOW [GLOBAL | SESSION] STATUS [LIKE 'pattern' | WHERE expr] SHOW STATUS provides server status information. This information also can be obtained using the mysqladmin extended-status command. The LIKE clause, if present, indicates which variable names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. With a LIKE clause, the statement displays only rows for those variables with names that match the pattern: mysql> SHOW STATUS LIKE 'Key%'; +--------------------+----------+ | Variable_name | Value | +--------------------+----------+ | Key_blocks_used | 14955 | | Key_read_requests | 96854827 | | Key_reads | 162040 | | Key_write_requests | 7589728 | | Key_writes | 3813196 | +--------------------+----------+ With the GLOBAL modifier, SHOW STATUS displays the status values for all connections to MySQL. With SESSION, it displays the status values for the current connection. If no modifier is present, the default is SESSION. LOCAL is a synonym for SESSION. Some status variables have only a global value. For these, you get the same value for both GLOBAL and SESSION. The scope for each status variable is listed at http://dev.mysql.com/doc/refman/5.1/en/server-status-variables.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show-status.html 7http://dev.mysql.com/doc/refman/5.1/en/show-status.html " EXTRACTVALUE$( Syntax: ExtractValue(xml_frag, xpath_expr) ExtractValue() takes two string arguments, a fragment of XML markup xml_frag and an XPath expression xpath_expr (also known as a locator); it returns the text (CDATA) of the first text node which is a child of the element(s) matched by the XPath expression. It is the equivalent of performing a match using the xpath_expr after appending /text(). In other words, ExtractValue('Sakila', '/a/b') and ExtractValue('Sakila', '/a/b/text()') produce the same result. If multiple matches are found, then the content of the first child text node of each matching element is returned (in the order matched) as a single, space-delimited string. If no matching text node is found for the expression (including the implicit /text()) --- for whatever reason, as long as xpath_expr is valid, and xml_frag consists of elements which are properly nested and closed --- an empty string is returned. No distinction is made between a match on an empty element and no match at all. This is by design. If you need to determine whether no matching element was found in xml_frag or such an element was found but contained no child text nodes, you should test the result of an expression that uses the XPath count() function. For example, both of these statements return an empty string, as shown here: mysql> SELECT ExtractValue('', '/a/b'); +-------------------------------------+ | ExtractValue('', '/a/b') | +-------------------------------------+ | | +-------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT ExtractValue('', '/a/b'); +-------------------------------------+ | ExtractValue('', '/a/b') | +-------------------------------------+ | | +-------------------------------------+ 1 row in set (0.00 sec) However, you can determine whether there was actually a matching element using the following: mysql> SELECT ExtractValue('', 'count(/a/b)'); +-------------------------------------+ | ExtractValue('', 'count(/a/b)') | +-------------------------------------+ | 1 | +-------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT ExtractValue('', 'count(/a/b)'); +-------------------------------------+ | ExtractValue('', 'count(/a/b)') | +-------------------------------------+ | 0 | +-------------------------------------+ 1 row in set (0.01 sec) *Important*: ExtractValue() returns only CDATA, and does not return any tags that might be contained within a matching tag, nor any of their content (see the result returned as val1 in the following example). URL: http://dev.mysql.com/doc/refman/5.1/en/xml-functions.html mysql> SELECT -> ExtractValue('cccddd', '/a') AS val1, -> ExtractValue('cccddd', '/a/b') AS val2, -> ExtractValue('cccddd', '//b') AS val3, -> ExtractValue('cccddd', '/b') AS val4, -> ExtractValue('cccdddeee', '//b') AS val5; +------+------+------+------+---------+ | val1 | val2 | val3 | val4 | val5 | +------+------+------+------+---------+ | ccc | ddd | ddd | | ddd eee | +------+------+------+------+---------+ 9http://dev.mysql.com/doc/refman/5.1/en/xml-functions.htmle2 OLD_PASSWORD Syntax: OLD_PASSWORD(str) OLD_PASSWORD() was added to MySQL when the implementation of PASSWORD() was changed to improve security. OLD_PASSWORD() returns the value of the old (pre-4.1) implementation of PASSWORD() as a binary string, and is intended to permit you to reset passwords for any pre-4.1 clients that need to connect to your version 5.1 MySQL server without locking them out. See http://dev.mysql.com/doc/refman/5.1/en/password-hashing.html. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.htmlc2 SET VARIABLESyntax: SET var_name = expr [, var_name = expr] ... The SET statement in stored programs is an extended version of the general SET statement (see [HELP SET]). Referenced variables may be ones declared inside a stored program, global system variables, or user-defined variables. The SET statement in stored programs is implemented as part of the pre-existing SET syntax. This allows an extended syntax of SET a=x, b=y, ... where different variable types (locally declared variables, global and session server variables, user-defined variables) can be mixed. This also allows combinations of local variables and some options that make sense only for system variables; in that case, the options are recognized but ignored. URL: http://dev.mysql.com/doc/refman/5.1/en/set-statement.html 9http://dev.mysql.com/doc/refman/5.1/en/set-statement.html "FORMAT$Syntax: FORMAT(X,D) Formats the number X to a format like '#,###,###.##', rounded to D decimal places, and returns the result as a string. If D is 0, the result has no decimal point or fractional part. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT FORMAT(12332.123456, 4); -> '12,332.1235' mysql> SELECT FORMAT(12332.1,4); -> '12,332.1000' mysql> SELECT FORMAT(12332.2,0); -> '12,332' SELECT 1 || 1; -> 1 mysql> SELECT 1 || 0; -> 1 mysql> SELECT 0 || 0; -> 0 mysql> SELECT 0 || NULL; -> NULL mysql> SELECT 1 || NULL; -> 1 =http://dev.mysql.com/doc/refman/5.1/en/logical-operators.html" BIT_LENGTH$Syntax: BIT_LENGTH(str) Returns the length of the string str in bits. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html 0mysql> SELECT BIT_LENGTH('text'); -> 32 SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT AsText(ExteriorRing(GeomFromText(@poly))); +-------------------------------------------+ | AsText(ExteriorRing(GeomFromText(@poly))) | +-------------------------------------------+ | LINESTRING(0 0,0 3,3 3,3 0,0 0) | +-------------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functionsM2 GEOMFROMWKB GeomFromWKB(wkb[,srid]), GeometryFromWKB(wkb[,srid]) Constructs a geometry value of any type using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functionsw2SHOW SLAVE HOSTS Syntax: SHOW SLAVE HOSTS Displays a list of replication slaves currently registered with the master. Only slaves started with the --report-host=host_name option are visible in this list. The list is displayed on any server (not just the master server). The output looks like this: mysql> SHOW SLAVE HOSTS; +------------+-----------+------+-----------+ | Server_id | Host | Port | Master_id | +------------+-----------+------+-----------+ | 192168010 | iconnect2 | 3306 | 192168011 | | 1921680101 | athena | 3306 | 192168011 | +------------+-----------+------+-----------+ o Server_id: The unique server ID of the slave server, as configured in the server's option file, or on the command line with --server-id=value. o Host: The host name of the slave server, as configured in the server's option file, or on the command line with --report-host=host_name. Note that this can differ from the machine name as configured in the operating system. o Port: The port the slave server is listening on. o Master_id: The unique server ID of the master server that the slave server is replicating from. Some MySQL versions report another variable, Rpl_recovery_rank. This variable was never used, and was eventually removed. URL: http://dev.mysql.com/doc/refman/5.1/en/show-slave-hosts.html SELECT 1 BETWEEN 2 AND 3; -> 0 mysql> SELECT 'b' BETWEEN 'a' AND 'c'; -> 1 mysql> SELECT 2 BETWEEN 2 AND '3'; -> 1 mysql> SELECT 2 BETWEEN 2 AND 'x-3'; -> 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html2 MULTIPOLYGONMultiPolygon(poly1,poly2,...) Constructs a WKB MultiPolygon value from a set of WKB Polygon arguments. If any argument is not a WKB Polygon, the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions" TIME_FORMAT!Syntax: TIME_FORMAT(time,format) This is used like the DATE_FORMAT() function, but the format string may contain format specifiers only for hours, minutes, and seconds. Other specifiers produce a NULL value or 0. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Wmysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l'); -> '100 100 04 04 4' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html9"LEFT$Syntax: LEFT(str,len) Returns the leftmost len characters from the string str, or NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html 7mysql> SELECT LEFT('foobarbar', 5); -> 'fooba' CREATE TABLE t (i INT); Query OK, 0 rows affected (0.42 sec) mysql> INSERT INTO t VALUES(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT i, RAND() FROM t; +------+------------------+ | i | RAND() | +------+------------------+ | 1 | 0.61914388706828 | | 2 | 0.93845168309142 | | 3 | 0.83482678498591 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND(3) FROM t; +------+------------------+ | i | RAND(3) | +------+------------------+ | 1 | 0.90576975597606 | | 2 | 0.37307905813035 | | 3 | 0.14808605345719 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND() FROM t; +------+------------------+ | i | RAND() | +------+------------------+ | 1 | 0.35877890638893 | | 2 | 0.28941420772058 | | 3 | 0.37073435016976 | +------+------------------+ 3 rows in set (0.00 sec) mysql> SELECT i, RAND(3) FROM t; +------+------------------+ | i | RAND(3) | +------+------------------+ | 1 | 0.90576975597606 | | 2 | 0.37307905813035 | | 3 | 0.14808605345719 | +------+------------------+ 3 rows in set (0.01 sec) Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"RPAD$ Syntax: RPAD(str,len,padstr) Returns the string str, right-padded with the string padstr to a length of len characters. If str is longer than len, the return value is shortened to len characters. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html bmysql> SELECT RPAD('hi',5,'?'); -> 'hi???' mysql> SELECT RPAD('hi',1,'?'); -> 'h' http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html"ELT$Syntax: ELT(N,str1,str2,str3,...) Returns str1 if N = 1, str2 if N = 2, and so on. Returns NULL if N is less than 1 or greater than the number of arguments. ELT() is the complement of FIELD(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT ELT(1, 'ej', 'Heja', 'hej', 'foo'); -> 'ej' mysql> SELECT ELT(4, 'ej', 'Heja', 'hej', 'foo'); -> 'foo' SELECT 5 & ~1; -> 4 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html}2TEXT.TEXT[(M)] [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 65,535 (216 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each TEXT value is stored using a two-byte length prefix that indicates the number of bytes in the value. An optional length M can be given for this type. If this is done, MySQL creates the column as the smallest TEXT type large enough to hold values M characters long. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html" CONCAT_WS$Syntax: CONCAT_WS(separator,str1,str2,...) CONCAT_WS() stands for Concatenate With Separator and is a special form of CONCAT(). The first argument is the separator for the rest of the arguments. The separator is added between the strings to be concatenated. The separator can be a string, as can the rest of the arguments. If the separator is NULL, the result is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT CONCAT_WS(',','First name','Second name','Last Name'); -> 'First name,Second name,Last Name' mysql> SELECT CONCAT_WS(',','First name',NULL,'Last Name'); -> 'First name,Last Name' INSERT INTO t VALUES(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 3 | +-------------+ 1 row in set (0.00 sec) mysql> DELETE FROM t WHERE i IN(1,2); Query OK, 2 rows affected (0.00 sec) mysql> SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 2 | +-------------+ 1 row in set (0.00 sec) Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html("ASINSyntax: ASIN(X) Returns the arc sine of X, that is, the value whose sine is X. Returns NULL if X is not in the range -1 to 1. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT ASIN(0.2); -> 0.20135792079033 mysql> SELECT ASIN('foo'); +-------------+ | ASIN('foo') | +-------------+ | 0 | +-------------+ 1 row in set, 1 warning (0.00 sec) mysql> SHOW WARNINGS; +---------+------+-----------------------------------------+ | Level | Code | Message | +---------+------+-----------------------------------------+ | Warning | 1292 | Truncated incorrect DOUBLE value: 'foo' | +---------+------+-----------------------------------------+ Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"SIGNSyntax: SIGN(X) Returns the sign of the argument as -1, 0, or 1, depending on whether X is negative, zero, or positive. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html qmysql> SELECT SIGN(-32); -> -1 mysql> SELECT SIGN(0); -> 0 mysql> SELECT SIGN(234); -> 1 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html" SEC_TO_TIMETSyntax: SEC_TO_TIME(seconds) Returns the seconds argument, converted to hours, minutes, and seconds, as a TIME value. The range of the result is constrained to that of the TIME data type. A warning occurs if the argument corresponds to a value outside that range. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html lmysql> SELECT SEC_TO_TIME(2378); -> '00:39:38' mysql> SELECT SEC_TO_TIME(2378) + 0; -> 3938 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2FLOATFLOAT[(M,D)] [UNSIGNED] [ZEROFILL] A small (single-precision) floating-point number. Allowable values are -3.402823466E+38 to -1.175494351E-38, 0, and 1.175494351E-38 to 3.402823466E+38. These are the theoretical limits, based on the IEEE standard. The actual range might be slightly smaller depending on your hardware or operating system. M is the total number of digits and D is the number of digits following the decimal point. If M and D are omitted, values are stored to the limits allowed by the hardware. A single-precision floating-point number is accurate to approximately 7 decimal places. UNSIGNED, if specified, disallows negative values. Using FLOAT might give you some unexpected problems because all calculations in MySQL are done with double precision. See http://dev.mysql.com/doc/refman/5.1/en/no-matching-rows.html. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.htmlm"LOCATE$xSyntax: LOCATE(substr,str), LOCATE(substr,str,pos) The first syntax returns the position of the first occurrence of substring substr in string str. The second syntax returns the position of the first occurrence of substring substr in string str, starting at position pos. Returns 0 if substr is not in str. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT LOCATE('bar', 'foobarbar'); -> 4 mysql> SELECT LOCATE('xbar', 'foobar'); -> 0 mysql> SELECT LOCATE('bar', 'foobarbar', 5); -> 7 SELECT CHARSET('abc'); -> 'latin1' mysql> SELECT CHARSET(CONVERT('abc' USING utf8)); -> 'utf8' mysql> SELECT CHARSET(USER()); -> 'utf8' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html62SUBDATESyntax: SUBDATE(date,INTERVAL expr unit), SUBDATE(expr,days) When invoked with the INTERVAL form of the second argument, SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD(). mysql> SELECT DATE_SUB('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02' mysql> SELECT SUBDATE('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02' The second form allows the use of an integer value for days. In such cases, it is interpreted as the number of days to be subtracted from the date or datetime expression expr. mysql> SELECT SUBDATE('2008-01-02 12:00:00', 31); -> '2007-12-02 12:00:00' URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html/" DAYOFYEARSyntax: DAYOFYEAR(date) Returns the day of the year for date, in the range 1 to 366. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 5mysql> SELECT DAYOFYEAR('2007-02-03'); -> 34 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2LONGTEXT3LONGTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 4,294,967,295 or 4GB (232 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. The effective maximum length of LONGTEXT columns also depends on the configured maximum packet size in the client/server protocol and available memory. Each LONGTEXT value is stored using a four-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.htmlf2%Syntax: N % M Modulo operation. Returns the remainder of N divided by M. For more information, see the description for the MOD() function in http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html. URL: http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html2KILLOSyntax: KILL [CONNECTION | QUERY] thread_id Each connection to mysqld runs in a separate thread. You can see which threads are running with the SHOW PROCESSLIST statement and kill a thread with the KILL thread_id statement. KILL allows the optional CONNECTION or QUERY modifier: o KILL CONNECTION is the same as KILL with no modifier: It terminates the connection associated with the given thread_id. o KILL QUERY terminates the statement that the connection is currently executing, but leaves the connection itself intact. If you have the PROCESS privilege, you can see all threads. If you have the SUPER privilege, you can kill all threads and statements. Otherwise, you can see and kill only your own threads and statements. You can also use the mysqladmin processlist and mysqladmin kill commands to examine and kill threads. *Note*: You cannot use KILL with the Embedded MySQL Server library, because the embedded server merely runs inside the threads of the host application. It does not create any connection threads of its own. URL: http://dev.mysql.com/doc/refman/5.1/en/kill.html 0http://dev.mysql.com/doc/refman/5.1/en/kill.htmlV2DISJOINTDisjoint(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially disjoint from (does not intersect) g2. URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html0"ASTEXTAsText(g), AsWKT(g) Converts a value in internal geometry format to its WKT representation and returns the string result. URL: http://dev.mysql.com/doc/refman/5.1/en/functions-to-convert-geometries-between-formats.html mysql> SET @g = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(GeomFromText(@g)); +--------------------------+ | AsText(GeomFromText(@g)) | +--------------------------+ | LINESTRING(1 1,2 2,3 3) | +--------------------------+ [http://dev.mysql.com/doc/refman/5.1/en/functions-to-convert-geometries-between-formats.html"LPAD$ Syntax: LPAD(str,len,padstr) Returns the string str, left-padded with the string padstr to a length of len characters. If str is longer than len, the return value is shortened to len characters. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html cmysql> SELECT LPAD('hi',4,'??'); -> '??hi' mysql> SELECT LPAD('hi',1,'??'); -> 'h' http://dev.mysql.com/doc/refman/5.1/en/declare-conditions.html2OVERLAPSrOverlaps(g1,g2) Returns 1 or 0 to indicate whether g1 spatially overlaps g2. The term spatially overlaps is used if two geometries intersect and their intersection results in a geometry of the same dimension but not equal to either of the given geometries. URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html2!SET GLOBAL SQL_SLAVE_SKIP_COUNTERmSyntax: SET GLOBAL SQL_SLAVE_SKIP_COUNTER = N This statement skips the next N events from the master. This is useful for recovering from replication stops caused by a statement. This statement is valid only when the slave thread is not running. Otherwise, it produces an error. URL: http://dev.mysql.com/doc/refman/5.1/en/set-global-sql-slave-skip-counter.html Mhttp://dev.mysql.com/doc/refman/5.1/en/set-global-sql-slave-skip-counter.html" NUMGEOMETRIESNumGeometries(gc) Returns the number of geometries in the GeometryCollection value gc. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#geometrycollection-property-functions 1mysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))'; mysql> SELECT NumGeometries(GeomFromText(@gc)); +----------------------------------+ | NumGeometries(GeomFromText(@gc)) | +----------------------------------+ | 2 | +----------------------------------+ mhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#geometrycollection-property-functions" MONTHNAMEBSyntax: MONTHNAME(date) Returns the full name of the month for date. As of MySQL 5.1.12, the language used for the name is controlled by the value of the lc_time_names system variable (http://dev.mysql.com/doc/refman/5.1/en/locale-support.html). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html =mysql> SELECT MONTHNAME('2008-02-03'); -> 'February' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2PROCEDURE ANALYSE%`Syntax: analyse([max_elements[,max_memory]]) This procedure is defined in the sql/sql_analyse.cc file. It examines the result from a query and returns an analysis of the results that suggests optimal data types for each column. To obtain this analysis, append PROCEDURE ANALYSE to the end of a SELECT statement: SELECT ... FROM ... WHERE ... PROCEDURE ANALYSE([max_elements,[max_memory]]) For example: SELECT col1, col2 FROM table1 PROCEDURE ANALYSE(10, 2000); The results show some statistics for the values returned by the query, and propose an optimal data type for the columns. This can be helpful for checking your existing tables, or after importing new data. You may need to try different settings for the arguments so that PROCEDURE ANALYSE() does not suggest the ENUM data type when it is not appropriate. The arguments are optional and are used as follows: o max_elements (default 256) is the maximum number of distinct values that analyse notices per column. This is used by analyse to check whether the optimal data type should be of type ENUM; if there are more than max_elements distinct values, then ENUM is not a suggested type. o max_memory (default 8192) is the maximum amount of memory that analyse should allocate per column while trying to find all distinct values. URL: http://dev.mysql.com/doc/refman/5.1/en/procedure-analyse.html =http://dev.mysql.com/doc/refman/5.1/en/procedure-analyse.html2CHANGE MASTER TOPSyntax: CHANGE MASTER TO master_def [, master_def] ... master_def: MASTER_BIND = 'interface_name' | MASTER_HOST = 'host_name' | MASTER_USER = 'user_name' | MASTER_PASSWORD = 'password' | MASTER_PORT = port_num | MASTER_CONNECT_RETRY = interval | MASTER_HEARTBEAT_PERIOD = interval | MASTER_LOG_FILE = 'master_log_name' | MASTER_LOG_POS = master_log_pos | RELAY_LOG_FILE = 'relay_log_name' | RELAY_LOG_POS = relay_log_pos | MASTER_SSL = {0|1} | MASTER_SSL_CA = 'ca_file_name' | MASTER_SSL_CAPATH = 'ca_directory_name' | MASTER_SSL_CERT = 'cert_file_name' | MASTER_SSL_KEY = 'key_file_name' | MASTER_SSL_CIPHER = 'cipher_list' | MASTER_SSL_VERIFY_SERVER_CERT = {0|1} CHANGE MASTER TO changes the parameters that the slave server uses for connecting to and communicating with the master server. It also updates the contents of the master.info and relay-log.info files. MASTER_USER, MASTER_PASSWORD, MASTER_SSL, MASTER_SSL_CA, MASTER_SSL_CAPATH, MASTER_SSL_CERT, MASTER_SSL_KEY, MASTER_SSL_CIPHER, and MASTER_SSL_VERIFY_SERVER_CERT provide information to the slave about how to connect to its master. MASTER_SSL_VERIFY_SERVER_CERT was added in MySQL 5.1.18. It is used as described for the --ssl-verify-server-cert option in http://dev.mysql.com/doc/refman/5.1/en/ssl-options.html. MASTER_CONNECT_RETRY specifies how many seconds to wait between connect retries. The default is 60. The number of reconnection attempts is limited by the --master-retry-count server option; for more information, see http://dev.mysql.com/doc/refman/5.1/en/replication-options.html. The SSL options (MASTER_SSL, MASTER_SSL_CA, MASTER_SSL_CAPATH, MASTER_SSL_CERT, MASTER_SSL_KEY, MASTER_SSL_CIPHER), and MASTER_SSL_VERIFY_SERVER_CERT can be changed even on slaves that are compiled without SSL support. They are saved to the master.info file, but are ignored unless you use a server that has SSL support enabled. If you don't specify a given parameter, it keeps its old value, except as indicated in the following discussion. For example, if the password to connect to your MySQL master has changed, you just need to issue these statements to tell the slave about the new password: STOP SLAVE; -- if replication was running CHANGE MASTER TO MASTER_PASSWORD='new3cret'; START SLAVE; -- if you want to restart replication There is no need to specify the parameters that do not change (host, port, user, and so forth). MASTER_HOST and MASTER_PORT are the hostname (or IP address) of the master host and its TCP/IP port. Note that if MASTER_HOST is equal to localhost, then, like in other parts of MySQL, the port number might be ignored. MASTER_BIND is for use on replication slaves having multiple network interfaces, and determines which of the slave's network interfaces is chosen for connecting to the master. It is also possible to determine which network interface is to be used in such cases by starting the slave mysqld process with the --master-bind option. The ability to bind a replication slave to specific network interface was added in MySQL Cluster NDB 6.3.4. MASTER_HEARTBEAT_PERIOD is used to set the interval in seconds between replication heartbeats. Whenever the master's binlog is updated with an event, the waiting period for the next heartbeat is reset. interval is a decimal value having the range 0 to 4294967 seconds and a resolution to hundredths of a second; the smallest nonzero value is 0.001. Heartbeats are sent by the master only if there are no unsent events in the binlog file for a period longer than interval. Setting interval to 0 disables heartbeats altogether. The default value for interval is equal to the value of slave_net_timeout divided by 2. *Note*: Setting @@global.slave_net_timeout to a value less than that of the current heartbeat interval results in a warning being issued. Issuing RESET SLAVE resets the heartbeat interval to the default. MASTER_HEARTBEAT_PERIOD was added in MySQL Cluster NDB 6.3.4. *Note*: Replication cannot use Unix socket files. You must be able to connect to the master MySQL server using TCP/IP. If you specify MASTER_HOST or MASTER_PORT, the slave assumes that the master server is different from before (even if you specify a host or port value that is the same as the current value.) In this case, the old values for the master binary log name and position are considered no longer applicable, so if you do not specify MASTER_LOG_FILE and MASTER_LOG_POS in the statement, MASTER_LOG_FILE='' and MASTER_LOG_POS=4 are silently appended to it. MASTER_LOG_FILE and MASTER_LOG_POS are the coordinates at which the slave I/O thread should begin reading from the master the next time the thread starts. If you specify either of them, you cannot specify RELAY_LOG_FILE or RELAY_LOG_POS. If neither of MASTER_LOG_FILE or MASTER_LOG_POS are specified, the slave uses the last coordinates of the slave SQL thread before CHANGE MASTER TO was issued. This ensures that there is no discontinuity in replication, even if the slave SQL thread was late compared to the slave I/O thread, when you merely want to change, say, the password to use. CHANGE MASTER TO deletes all relay log files and starts a new one, unless you specify RELAY_LOG_FILE or RELAY_LOG_POS. In that case, relay logs are kept; the relay_log_purge global variable is set silently to 0. CHANGE MASTER TO is useful for setting up a slave when you have the snapshot of the master and have recorded the log and the offset corresponding to it. After loading the snapshot into the slave, you can run CHANGE MASTER TO MASTER_LOG_FILE='log_name_on_master', MASTER_LOG_POS=log_offset_on_master on the slave. The following example changes the master and master's binary log coordinates. This is used when you want to set up the slave to replicate the master: CHANGE MASTER TO MASTER_HOST='master2.mycompany.com', MASTER_USER='replication', MASTER_PASSWORD='bigs3cret', MASTER_PORT=3306, MASTER_LOG_FILE='master2-bin.001', MASTER_LOG_POS=4, MASTER_CONNECT_RETRY=10; The next example shows an operation that is less frequently employed. It is used when the slave has relay logs that you want it to execute again for some reason. To do this, the master need not be reachable. You need only use CHANGE MASTER TO and start the SQL thread (START SLAVE SQL_THREAD): CHANGE MASTER TO RELAY_LOG_FILE='slave-relay-bin.006', RELAY_LOG_POS=4025; URL: http://dev.mysql.com/doc/refman/5.1/en/change-master-to.html SELECT TIMESTAMP('2003-12-31'); -> '2003-12-31 00:00:00' mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00'); -> '2004-01-01 00:00:00' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2CHARACTER_LENGTH$Syntax: CHARACTER_LENGTH(str) CHARACTER_LENGTH() is a synonym for CHAR_LENGTH(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SHOW GRANTS FOR 'root'@'localhost'; +---------------------------------------------------------------------+ | Grants for root@localhost | +---------------------------------------------------------------------+ | GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION | +---------------------------------------------------------------------+ To list the privileges granted to the account that you are using to connect to the server, you can use any of the following statements: SHOW GRANTS; SHOW GRANTS FOR CURRENT_USER; SHOW GRANTS FOR CURRENT_USER(); As of MySQL 5.1.12, if SHOW GRANTS FOR CURRENT_USER (or any of the equivalent syntaxes) is used in DEFINER context, such as within a stored procedure that is defined with SQL SECURITY DEFINER), the grants displayed are those of the definer and not the invoker. URL: http://dev.mysql.com/doc/refman/5.1/en/show-grants.html 7http://dev.mysql.com/doc/refman/5.1/en/show-grants.htmlI2SHOW PRIVILEGESSyntax: SHOW PRIVILEGES SHOW PRIVILEGES shows the list of system privileges that the MySQL server supports. The exact list of privileges depends on the version of your server. URL: http://dev.mysql.com/doc/refman/5.1/en/show-privileges.html ;http://dev.mysql.com/doc/refman/5.1/en/show-privileges.html2CREATE TABLESPACE&Syntax: CREATE TABLESPACE tablespace_name ADD DATAFILE 'file_name' USE LOGFILE GROUP logfile_group [EXTENT_SIZE [=] extent_size] [INITIAL_SIZE [=] initial_size] [AUTOEXTEND_SIZE [=] autoextend_size] [MAX_SIZE [=] max_size] [NODEGROUP [=] nodegroup_id] [WAIT] [COMMENT [=] comment_text] ENGINE [=] engine_name This statement is used to create a tablespace, which can contain one or more data files, providing storage space for tables. One data file is created and added to the tablespace using this statement. Additional data files may be added to the tablespace by using the ALTER TABLESPACE statement (see [HELP ALTER TABLESPACE]). For rules covering the naming of tablespaces, see http://dev.mysql.com/doc/refman/5.1/en/identifiers.html. A log file group of one or more UNDO log files must be assigned to the tablespace to be created with the USE LOGFILE GROUP clause. logfile_group must be an existing log file group created with CREATE LOGFILE GROUP (see http://dev.mysql.com/doc/refman/5.1/en/create-logfile-group.html). Multiple tablespaces may use the same log file group for UNDO logging. The EXTENT_SIZE sets the size, in bytes, of the extents used by any files belonging to the tablespace. The default value is 1M. The minimum size is 32K, and theoretical maximum is 2G, although the practical maximum size depends on a number of factors. In most cases, changing the extent size does not have any measurable effect on performance, and the default value is recommended for all but the most unusual situations. An extent is a unit of disk space allocation. One extent is filled with as much data as that extent can contain before another extent is used. In theory, up to 65,535 (64K) extents may used per data file; however, the recommended maximum is 32,768 (32K). The recommended maximum size for a single data file is 32G --- that is, 32K extents x 1 MB per extent. In addition, once an extent is allocated to a given partition, it cannot be used to store data from a different partition; an extent cannot store data from more than one partition. This means, for example that a tablespace having a single datafile whose INITIAL_SIZE is 256 MB and whose EXTENT_SIZE is 128M has just two extents, and so can be used to store data from at most two different disk data table partitions. You can see how many extents remain free in a given data file by querying the INFORMATION_SCHEMA.FILES table, and so derive an estimate for how much space remains free in the file. For further discussion and examples, see http://dev.mysql.com/doc/refman/5.1/en/files-table.html. The INITIAL_SIZE parameter sets the data file's total size in bytes. Once the file has been created, its size cannot be changed; however, you can add more data files to the tablespace using ALTER TABLESPACE ... ADD DATAFILE. See [HELP ALTER TABLESPACE]. INITIAL_SIZE is optional; its default value is 128M. On 32-bit systems, the maximum supported value for INITIAL_SIZE is 4G. (Bug#29186 (http://bugs.mysql.com/29186)) When setting EXTENT_SIZE or INITIAL_SIZE (either or both), you may optionally follow the number with a one-letter abbreviation for an order of magnitude, similar to those used in my.cnf. Generally, this is one of the letters M (for megabytes) or G (for gigabytes). AUTOEXTEND_SIZE, MAX_SIZE, NODEGROUP, WAIT, and COMMENT are parsed but ignored, and so have no effect in MySQL 5.1. These options are intended for future expansion. The ENGINE parameter determines the storage engine which uses this tablespace, with engine_name being the name of the storage engine. In MySQL 5.1, engine_name must be one of the values NDB or NDBCLUSTER. When CREATE TABLESPACE is used with ENGINE = NDB, a tablespace and associated data file are created on each Cluster data node. You can verify that the data files were created and obtain information about them by querying the INFORMATION_SCHEMA.FILES table. For example: mysql> SELECT LOGFILE_GROUP_NAME, FILE_NAME, EXTRA -> FROM INFORMATION_SCHEMA.FILES -> WHERE TABLESPACE_NAME = 'newts' AND FILE_TYPE = 'DATAFILE'; +--------------------+-------------+----------------+ | LOGFILE_GROUP_NAME | FILE_NAME | EXTRA | +--------------------+-------------+----------------+ | lg_3 | newdata.dat | CLUSTER_NODE=3 | | lg_3 | newdata.dat | CLUSTER_NODE=4 | +--------------------+-------------+----------------+ 2 rows in set (0.01 sec) (See http://dev.mysql.com/doc/refman/5.1/en/files-table.html.) CREATE TABLESPACE was added in MySQL 5.1.6. In MySQL 5.1, it is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-disk-data.html. URL: http://dev.mysql.com/doc/refman/5.1/en/create-tablespace.html =http://dev.mysql.com/doc/refman/5.1/en/create-tablespace.html"INSERT FUNCTION$Syntax: INSERT(str,pos,len,newstr) Returns the string str, with the substring beginning at position pos and len characters long replaced by the string newstr. Returns the original string if pos is not within the length of the string. Replaces the rest of the string from position pos if len is not within the length of the rest of the string. Returns NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT INSERT('Quadratic', 3, 4, 'What'); -> 'QuWhattic' mysql> SELECT INSERT('Quadratic', -1, 4, 'What'); -> 'Quadratic' mysql> SELECT INSERT('Quadratic', 3, 100, 'What'); -> 'QuWhat' SELECT CRC32('MySQL'); -> 3259397556 mysql> SELECT CRC32('mysql'); -> 2501908538 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"XOR Syntax: XOR Logical XOR. Returns NULL if either operand is NULL. For non-NULL operands, evaluates to 1 if an odd number of operands is non-zero, otherwise 0 is returned. URL: http://dev.mysql.com/doc/refman/5.1/en/logical-operators.html mysql> SELECT 1 XOR 1; -> 0 mysql> SELECT 1 XOR 0; -> 1 mysql> SELECT 1 XOR NULL; -> NULL mysql> SELECT 1 XOR 1 XOR 1; -> 1 =http://dev.mysql.com/doc/refman/5.1/en/logical-operators.htmlr" STARTPOINT StartPoint(ls) Returns the Point that is the start point of the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions 3mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(StartPoint(GeomFromText(@ls))); +---------------------------------------+ | AsText(StartPoint(GeomFromText(@ls))) | +---------------------------------------+ | POINT(1 1) | +---------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions2DECLARE VARIABLE=Syntax: DECLARE var_name [, var_name] ... type [DEFAULT value] This statement is used to declare local variables within stored programs. To provide a default value for the variable, include a DEFAULT clause. The value can be specified as an expression; it need not be a constant. If the DEFAULT clause is missing, the initial value is NULL. Local variables are treated like stored routine parameters with respect to data type and overflow checking. See [HELP CREATE PROCEDURE]. Local variable names are not case sensitive. The scope of a local variable is within the BEGIN ... END block where it is declared. The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name. URL: http://dev.mysql.com/doc/refman/5.1/en/declare-local-variables.html Chttp://dev.mysql.com/doc/refman/5.1/en/declare-local-variables.htmlc2GRANT "Syntax: GRANT priv_type [(column_list)] [, priv_type [(column_list)]] ... ON [object_type] { * | *.* | db_name.* | db_name.tbl_name | tbl_name | db_name.routine_name } TO user [IDENTIFIED BY [PASSWORD] 'password'] [, user [IDENTIFIED BY [PASSWORD] 'password']] ... [REQUIRE NONE | [{SSL| X509}] [CIPHER 'cipher' [AND]] [ISSUER 'issuer' [AND]] [SUBJECT 'subject']] [WITH with_option [with_option] ...] object_type = TABLE | FUNCTION | PROCEDURE with_option = GRANT OPTION | MAX_QUERIES_PER_HOUR count | MAX_UPDATES_PER_HOUR count | MAX_CONNECTIONS_PER_HOUR count | MAX_USER_CONNECTIONS count The GRANT statement enables system administrators to create MySQL user accounts and to grant rights to accounts. To use GRANT, you must have the GRANT OPTION privilege, and you must have the privileges that you are granting. The REVOKE statement is related and enables administrators to remove account privileges. See [HELP REVOKE]. MySQL account information is stored in the tables of the mysql database. This database and the access control system are discussed extensively in http://dev.mysql.com/doc/refman/5.1/en/server-administration.html, which you should consult for additional details. *Important*: Some releases of MySQL introduce changes to the structure of the grant tables to add new privileges or features. Whenever you update to a new version of MySQL, you should update your grant tables to make sure that they have the current structure so that you can take advantage of any new capabilities. See http://dev.mysql.com/doc/refman/5.1/en/mysql-upgrade.html. If the grant tables hold privilege rows that contain mixed-case database or table names and the lower_case_table_names system variable is set to a non-zero value, REVOKE cannot be used to revoke these privileges. It will be necessary to manipulate the grant tables directly. (GRANT will not create such rows when lower_case_table_names is set, but such rows might have been created prior to setting the variable.) Privileges can be granted at several levels. The examples shown here include no IDENTIFIED BY 'password' clause for brevity, but you should include one if the account does not already exist to avoid creating an account with no password. o Global level Global privileges apply to all databases on a given server. These privileges are stored in the mysql.user table. GRANT ALL ON *.* and REVOKE ALL ON *.* grant and revoke only global privileges. GRANT ALL ON *.* TO 'someuser'@'somehost'; GRANT SELECT, INSERT ON *.* TO 'someuser'@'somehost'; o Database level Database privileges apply to all objects in a given database. These privileges are stored in the mysql.db and mysql.host tables. GRANT ALL ON db_name.* and REVOKE ALL ON db_name.* grant and revoke only database privileges. GRANT ALL ON mydb.* TO 'someuser'@'somehost'; GRANT SELECT, INSERT ON mydb.* TO 'someuser'@'somehost'; o Table level Table privileges apply to all columns in a given table. These privileges are stored in the mysql.tables_priv table. GRANT ALL ON db_name.tbl_name and REVOKE ALL ON db_name.tbl_name grant and revoke only table privileges. GRANT ALL ON mydb.mytbl TO 'someuser'@'somehost'; GRANT SELECT, INSERT ON mydb.mytbl TO 'someuser'@'somehost'; If you specify tbl_name rather than db_name.tbl_name, the statement applies to tbl_name in the default database. o Column level Column privileges apply to single columns in a given table. These privileges are stored in the mysql.columns_priv table. When using REVOKE, you must specify the same columns that were granted. The column or columns for which the privileges are to be granted must be enclosed within parentheses. GRANT SELECT (col1), INSERT (col1,col2) ON mydb.mytbl TO 'someuser'@'somehost'; o Routine level The CREATE ROUTINE, ALTER ROUTINE, EXECUTE, and GRANT OPTION privileges apply to stored routines (functions and procedures). They can be granted at the global and database levels. Also, except for CREATE ROUTINE, these privileges can be granted at the routine level for individual routines and are stored in the mysql.procs_priv table. GRANT CREATE ROUTINE ON mydb.* TO 'someuser'@'somehost'; GRANT EXECUTE ON PROCEDURE mydb.myproc TO 'someuser'@'somehost'; The object_type clause should be specified as TABLE, FUNCTION, or PROCEDURE when the following object is a table, a stored function, or a stored procedure. URL: http://dev.mysql.com/doc/refman/5.1/en/grant.html 1http://dev.mysql.com/doc/refman/5.1/en/grant.htmlN2 MPOLYFROMTEXTMPolyFromText(wkt[,srid]), MultiPolygonFromText(wkt[,srid]) Constructs a MULTIPOLYGON value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions.2 MBRINTERSECTSMBRIntersects(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 intersect. URL: http://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html Ehttp://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html2BIT_ORSyntax: BIT_OR(expr) Returns the bitwise OR of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html"YEARWEEKTSyntax: YEARWEEK(date), YEARWEEK(date,mode) Returns year and week for a date. The mode argument works exactly like the mode argument to WEEK(). The year in the result may be different from the year in the date argument for the first and the last week of the year. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 8mysql> SELECT YEARWEEK('1987-01-01'); -> 198653 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2 NOT BETWEENSyntax: expr NOT BETWEEN min AND max This is the same as NOT (expr BETWEEN min AND max). URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.htmln"IS NOTSyntax: IS NOT boolean_value Tests a value against a boolean value, where boolean_value can be TRUE, FALSE, or UNKNOWN. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html Zmysql> SELECT 1 IS NOT UNKNOWN, 0 IS NOT UNKNOWN, NULL IS NOT UNKNOWN; -> 1, 1, 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.htmlZ"LOG10Syntax: LOG10(X) Returns the base-10 logarithm of X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT LOG10(2); -> 0.30102999566398 mysql> SELECT LOG10(100); -> 2 mysql> SELECT LOG10(-100); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlj"SQRTSyntax: SQRT(X) Returns the square root of a non-negative number X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT SQRT(4); -> 2 mysql> SELECT SQRT(20); -> 4.4721359549996 mysql> SELECT SQRT(-16); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html-2DECIMALDECIMAL[(M[,D])] [UNSIGNED] [ZEROFILL] A packed "exact" fixed-point number. M is the total number of digits (the precision) and D is the number of digits after the decimal point (the scale). The decimal point and (for negative numbers) the "-" sign are not counted in M. If D is 0, values have no decimal point or fractional part. The maximum number of digits (M) for DECIMAL is 65. The maximum number of supported decimals (D) is 30. If D is omitted, the default is 0. If M is omitted, the default is 10. UNSIGNED, if specified, disallows negative values. All basic calculations (+, -, *, /) with DECIMAL columns are done with a precision of 65 digits. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html2 CREATE INDEX&Syntax: CREATE [ONLINE|OFFLINE] [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type] ON tbl_name (index_col_name,...) [index_option] ... index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name CREATE INDEX is mapped to an ALTER TABLE statement to create indexes. See [HELP ALTER TABLE]. CREATE INDEX cannot be used to create a PRIMARY KEY; use ALTER TABLE instead. For more information about indexes, see http://dev.mysql.com/doc/refman/5.1/en/mysql-indexes.html. URL: http://dev.mysql.com/doc/refman/5.1/en/create-index.html 8http://dev.mysql.com/doc/refman/5.1/en/create-index.html2CREATE FUNCTION&VThe CREATE FUNCTION statement is used to create stored functions and user-defined functions (UDFs): o For information about creating stored functions, see [HELP CREATE PROCEDURE]. o For information about creating user-defined functions, see [HELP CREATE FUNCTION UDF]. URL: http://dev.mysql.com/doc/refman/5.1/en/create-function.html ;http://dev.mysql.com/doc/refman/5.1/en/create-function.html 2ALTER DATABASE& Syntax: ALTER {DATABASE | SCHEMA} [db_name] alter_specification ... ALTER {DATABASE | SCHEMA} db_name UPGRADE DATA DIRECTORY NAME alter_specification: [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name ALTER DATABASE enables you to change the overall characteristics of a database. These characteristics are stored in the db.opt file in the database directory. To use ALTER DATABASE, you need the ALTER privilege on the database. ALTER SCHEMA is a synonym for ALTER DATABASE. The CHARACTER SET clause changes the default database character set. The COLLATE clause changes the default database collation. http://dev.mysql.com/doc/refman/5.1/en/charset.html, discusses character set and collation names. You can see what character sets and collations are available using, respectively, the SHOW CHARACTER SET and SHOW COLLATION statements. See [HELP SHOW CHARACTER SET], and [HELP SHOW COLLATION], for more information. The database name can be omitted from the first syntax, in which case the statement applies to the default database. The syntax that includes the UPGRADE DATA DIRECTORY NAME clause was added in MySQL 5.1.23. It updates the name of the directory associated with the database to use the encoding implemented in MySQL 5.1 for mapping database names to database directory names (see http://dev.mysql.com/doc/refman/5.1/en/identifier-mapping.html). This clause is for use under these conditions: o It is intended when upgrading MySQL to 5.1 or later from older versions. o It is intended to update a database directory name to the current encoding format if the name contains special characters that need encoding. o The statement is used by mysqlcheck (as invoked by mysql_upgrade). For example,if a database in MySQL 5.0 has a name of a-b-c, the name contains instance of the `-' character. In 5.0, the database directory is also named a-b-c, which is not necessarily safe for all filesystems. In MySQL 5.1 and up, the same database name is encoded as a@002db@002dc to produce a filesystem-neutral directory name. When a MySQL installation is upgraded to MySQL 5.1 or later from an older version,the server displays a name such as a-b-c (which is in the old format) as #mysql50#a-b-c, and you must refer to the name using the #mysql50# prefix. Use UPGRADE DATA DIRECTORY NAME in this case to explicitly tell the server to re-encode the database directory name to the current encoding format: ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME; After executing this statement, you can refer to the database as a-b-c without the special #mysql50# prefix. URL: http://dev.mysql.com/doc/refman/5.1/en/alter-database.html :http://dev.mysql.com/doc/refman/5.1/en/alter-database.html" GEOMETRYNGeometryN(gc,N) Returns the N-th geometry in the GeometryCollection value gc. Geometries are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#geometrycollection-property-functions Umysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))'; mysql> SELECT AsText(GeometryN(GeomFromText(@gc),1)); +----------------------------------------+ | AsText(GeometryN(GeomFromText(@gc),1)) | +----------------------------------------+ | POINT(1 1) | +----------------------------------------+ mhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#geometrycollection-property-functions"<<|Syntax: << Shifts a longlong (BIGINT) number to the left. URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html #mysql> SELECT 1 << 2; -> 4 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.htmlz2SHOW TABLE STATUS!Syntax: SHOW TABLE STATUS [FROM db_name] [LIKE 'pattern' | WHERE expr] SHOW TABLE STATUS works likes SHOW TABLES, but provides a lot of information about each non-TEMPORARY table. You can also get this list using the mysqlshow --status db_name command. The LIKE clause, if present, indicates which table names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show-table-status.html =http://dev.mysql.com/doc/refman/5.1/en/show-table-status.html"MD5 $Syntax: MD5(str) Calculates an MD5 128-bit checksum for the string. The value is returned as a binary string of 32 hex digits, or NULL if the argument was NULL. The return value can, for example, be used as a hash key. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html Lmysql> SELECT MD5('testing'); -> 'ae2b1fca515949e5d54fb22b8ed95575' @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html"<^Syntax: < Less than: URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html "mysql> SELECT 2 < 2; -> 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"UNIX_TIMESTAMPSyntax: UNIX_TIMESTAMP(), UNIX_TIMESTAMP(date) If called with no argument, returns a Unix timestamp (seconds since '1970-01-01 00:00:00' UTC) as an unsigned integer. If UNIX_TIMESTAMP() is called with a date argument, it returns the value of the argument as seconds since '1970-01-01 00:00:00' UTC. date may be a DATE string, a DATETIME string, a TIMESTAMP, or a number in the format YYMMDD or YYYYMMDD. The server interprets date as a value in the current time zone and converts it to an internal value in UTC. Clients can set their time zone as described in http://dev.mysql.com/doc/refman/5.1/en/time-zone-support.html. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT UNIX_TIMESTAMP(); -> 1196440210 mysql> SELECT UNIX_TIMESTAMP('2007-11-30 10:30:19'); -> 1196440219 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" DAYOFMONTHSyntax: DAYOFMONTH(date) Returns the day of the month for date, in the range 1 to 31, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero day part. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 5mysql> SELECT DAYOFMONTH('2007-02-03'); -> 3 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"ASCII$Syntax: ASCII(str) Returns the numeric value of the leftmost character of the string str. Returns 0 if str is the empty string. Returns NULL if str is NULL. ASCII() works for 8-bit characters. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html xmysql> SELECT ASCII('2'); -> 50 mysql> SELECT ASCII(2); -> 50 mysql> SELECT ASCII('dx'); -> 100 SELECT 5 DIV 2; -> 2 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html2 RENAME USER Syntax: RENAME USER old_user TO new_user [, old_user TO new_user] ... The RENAME USER statement renames existing MySQL accounts. To use it, you must have the global CREATE USER privilege or the UPDATE privilege for the mysql database. An error occurs if any old account does not exist or any new account exists. Each account is named using the same format as for the GRANT statement; for example, 'jeffrey'@'localhost'. If you specify only the username part of the account name, a hostname part of '%' is used. For additional information about specifying account names, see [HELP GRANT]. URL: http://dev.mysql.com/doc/refman/5.1/en/rename-user.html 7http://dev.mysql.com/doc/refman/5.1/en/rename-user.html2SHOW SLAVE STATUSiSyntax: SHOW SLAVE STATUS This statement provides status information on essential parameters of the slave threads. If you issue this statement using the mysql client, you can use a \G statement terminator rather than a semicolon to obtain a more readable vertical layout: mysql> SHOW SLAVE STATUS\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: localhost Master_User: root Master_Port: 3306 Connect_Retry: 3 Master_Log_File: gbichot-bin.005 Read_Master_Log_Pos: 79 Relay_Log_File: gbichot-relay-bin.005 Relay_Log_Pos: 548 Relay_Master_Log_File: gbichot-bin.005 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 79 Relay_Log_Space: 552 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 8 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: URL: http://dev.mysql.com/doc/refman/5.1/en/show-slave-status.html =http://dev.mysql.com/doc/refman/5.1/en/show-slave-status.html"GEOMETRY!dMySQL provides a standard way of creating spatial columns for geometry types, for example, with CREATE TABLE or ALTER TABLE. Currently, spatial columns are supported for MyISAM, InnoDB, NDB, and ARCHIVE tables. See also the annotations about spatial indexes under [HELP SPATIAL]. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-columns.html CREATE TABLE geom (g GEOMETRY); Dhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-columns.html4" NUMPOINTS NumPoints(ls) Returns the number of Point objects in the LineString value ls. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT NumPoints(GeomFromText(@ls)); +------------------------------+ | NumPoints(GeomFromText(@ls)) | +------------------------------+ | 3 | +------------------------------+ ehttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions"&YSyntax: & Bitwise AND: URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html %mysql> SELECT 29 & 15; -> 13 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html 2LOCALTIMESTAMPSyntax: LOCALTIMESTAMP, LOCALTIMESTAMP() LOCALTIMESTAMP and LOCALTIMESTAMP() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmly"CONVERT$Syntax: CONVERT(expr,type), CONVERT(expr USING transcoding_name) The CONVERT() and CAST() functions take a value of one type and produce a value of another type. The type can be one of the following values: o BINARY[(N)] o CHAR[(N)] o DATE o DATETIME o DECIMAL[(M[,D])] o SIGNED [INTEGER] o TIME o UNSIGNED [INTEGER] BINARY produces a string with the BINARY data type. See http://dev.mysql.com/doc/refman/5.1/en/binary-varbinary.html for a description of how this affects comparisons. If the optional length N is given, BINARY(N) causes the cast to use no more than N bytes of the argument. Values shorter than N bytes are padded with 0x00 bytes to a length of N. CHAR(N) causes the cast to use no more than N characters of the argument. CAST() and CONVERT(... USING ...) are standard SQL syntax. The non-USING form of CONVERT() is ODBC syntax. CONVERT() with USING is used to convert data between different character sets. In MySQL, transcoding names are the same as the corresponding character set names. For example, this statement converts the string 'abc' in the default character set to the corresponding string in the utf8 character set: SELECT CONVERT('abc' USING utf8); URL: http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html ?SELECT enum_col FROM tbl_name ORDER BY CAST(enum_col AS CHAR); :http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html+"ADDDATESyntax: ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days) When invoked with the INTERVAL form of the second argument, ADDDATE() is a synonym for DATE_ADD(). The related function SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD(). mysql> SELECT DATE_ADD('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02' mysql> SELECT ADDDATE('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02' When invoked with the days form of the second argument, MySQL treats it as an integer number of days to be added to expr. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Amysql> SELECT ADDDATE('2008-01-02', 31); -> '2008-02-02' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" REPEAT LOOP/Syntax: [begin_label:] REPEAT statement_list UNTIL search_condition END REPEAT [end_label] The statement list within a REPEAT statement is repeated until the search_condition is true. Thus, a REPEAT always enters the loop at least once. statement_list consists of one or more statements, each terminated by a semicolon (;) statement delimiter. A REPEAT statement can be labeled. end_label cannot be given unless begin_label also is present. If both are present, they must be the same. URL: http://dev.mysql.com/doc/refman/5.1/en/repeat-statement.html qmysql> delimiter // mysql> CREATE PROCEDURE dorepeat(p1 INT) -> BEGIN -> SET @x = 0; -> REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT; -> END -> // Query OK, 0 rows affected (0.00 sec) mysql> CALL dorepeat(1000)// Query OK, 0 rows affected (0.00 sec) mysql> SELECT @x// +------+ | @x | +------+ | 1001 | +------+ 1 row in set (0.00 sec) SELECT ORD('2'); -> 50 SELECT AsText(Envelope(GeomFromText('LineString(1 1,2 2)'))); +-------------------------------------------------------+ | AsText(Envelope(GeomFromText('LineString(1 1,2 2)'))) | +-------------------------------------------------------+ | POLYGON((1 1,2 1,2 2,1 2,1 1)) | +-------------------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions2 IS_FREE_LOCK>Syntax: IS_FREE_LOCK(str) Checks whether the lock named str is free to use (that is, not locked). Returns 1 if the lock is free (no one is using the lock), 0 if the lock is in use, and NULL if an error occurs (such as an incorrect argument). URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html2TOUCHESwTouches(g1,g2) Returns 1 or 0 to indicate whether g1 spatially touches g2. Two geometries spatially touch if the interiors of the geometries do not intersect, but the boundary of one of the geometries intersects either the boundary or the interior of the other. URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html" INET_ATONSyntax: INET_ATON(expr) Given the dotted-quad representation of a network address as a string, returns an integer that represents the numeric value of the address. Addresses may be 4- or 8-byte addresses. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Amysql> SELECT INET_ATON('209.207.224.40'); -> 3520061480 Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.htmlO" UNCOMPRESS vSyntax: UNCOMPRESS(string_to_uncompress) Uncompresses a string compressed by the COMPRESS() function. If the argument is not a compressed value, the result is NULL. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html mysql> SELECT UNCOMPRESS(COMPRESS('any string')); -> 'any string' mysql> SELECT UNCOMPRESS('any string'); -> NULL @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html"AUTO_INCREMENTThe AUTO_INCREMENT attribute can be used to generate a unique identity for new rows: URL: http://dev.mysql.com/doc/refman/5.1/en/example-auto-increment.html CREATE TABLE animals ( id MEDIUMINT NOT NULL AUTO_INCREMENT, name CHAR(30) NOT NULL, PRIMARY KEY (id) ); INSERT INTO animals (name) VALUES ('dog'),('cat'),('penguin'), ('lax'),('whale'),('ostrich'); SELECT * FROM animals; Bhttp://dev.mysql.com/doc/refman/5.1/en/example-auto-increment.html2ISSIMPLE#IsSimple(g) Currently, this function is a placeholder and should not be used. If implemented, its behavior will be as described in the next paragraph. Returns 1 if the geometry value g has no anomalous geometric points, such as self-intersection or self-tangency. IsSimple() returns 0 if the argument is not simple, and -1 if it is NULL. The description of each instantiable geometric class given earlier in the chapter includes the specific conditions that cause an instance of that class to be classified as not simple. (See [HELP Geometry hierarchy].) URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions"- BINARY`Syntax: - Subtraction: URL: http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html !mysql> SELECT 3-5; -> -2 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html`2GEOMCOLLFROMTEXTGeomCollFromText(wkt[,srid]), GeometryCollectionFromText(wkt[,srid]) Constructs a GEOMETRYCOLLECTION value using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions2WKT DEFINITIONThe Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form. URL: http://dev.mysql.com/doc/refman/5.1/en/gis-wkt-format.html :http://dev.mysql.com/doc/refman/5.1/en/gis-wkt-format.html2 CURRENT_TIMESyntax: CURRENT_TIME, CURRENT_TIME() CURRENT_TIME and CURRENT_TIME() are synonyms for CURTIME(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmli2REVOKE &Syntax: REVOKE priv_type [(column_list)] [, priv_type [(column_list)]] ... ON [object_type] { * | *.* | db_name.* | db_name.tbl_name | tbl_name | db_name.routine_name } FROM user [, user] ... REVOKE ALL PRIVILEGES, GRANT OPTION FROM user [, user] ... The REVOKE statement enables system administrators to revoke privileges from MySQL accounts. Each account is named using the same format as for the GRANT statement; for example, 'jeffrey'@'localhost'. If you specify only the username part of the account name, a hostname part of '%' is used. For additional information about specifying account names, see [HELP GRANT]. To use the first REVOKE syntax, you must have the GRANT OPTION privilege, and you must have the privileges that you are revoking. For details on the levels at which privileges exist, the allowable priv_type values, and the syntax for specifying users and passwords, see [HELP GRANT] URL: http://dev.mysql.com/doc/refman/5.1/en/revoke.html 2http://dev.mysql.com/doc/refman/5.1/en/revoke.html 2LAST_INSERT_IDt Syntax: LAST_INSERT_ID(), LAST_INSERT_ID(expr) For MySQL 5.1.12 and later, LAST_INSERT_ID() (no arguments) returns the first automatically generated value successfully inserted for an AUTO_INCREMENT column as a result of the most recently executed INSERT statement. The value of LAST_INSERT_ID() remains unchanged if no rows are successfully inserted. For example, after inserting a row that generates an AUTO_INCREMENT value, you can get the value like this: mysql> SELECT LAST_INSERT_ID(); -> 195 In MySQL 5.1.11 and earlier, LAST_INSERT_ID() (no arguments) returns the first automatically generated value if any rows were successfully inserted or updated. This means that the returned value could be a value that was not successfully inserted into the table. If no rows were successfully inserted, LAST_INSERT_ID() returns 0. The value of LAST_INSERT_ID() will be consistent across all versions if all rows in the INSERT or UPDATE statement were successful. if a table contains an AUTO_INCREMENT column and INSERT ... ON DUPLICATE KEY UPDATE updates (rather than inserts) a row, the value of LAST_INSERT_ID() is not meaningful prior to MySQL 5.1.12. For a workaround, see http://dev.mysql.com/doc/refman/5.1/en/insert-on-duplicate.html. The currently executing statement does not affect the value of LAST_INSERT_ID(). Suppose that you generate an AUTO_INCREMENT value with one statement, and then refer to LAST_INSERT_ID() in a multiple-row INSERT statement that inserts rows into a table with its own AUTO_INCREMENT column. The value of LAST_INSERT_ID() will remain stable in the second statement; its value for the second and later rows is not affected by the earlier row insertions. (However, if you mix references to LAST_INSERT_ID() and LAST_INSERT_ID(expr), the effect is undefined.) If the previous statement returned an error, the value of LAST_INSERT_ID() is undefined. For transactional tables, if the statement is rolled back due to an error, the value of LAST_INSERT_ID() is left undefined. For manual ROLLBACK, the value of LAST_INSERT_ID() is not restored to that before the transaction; it remains as it was at the point of the ROLLBACK. Within the body of a stored routine (procedure or function) or a trigger, the value of LAST_INSERT_ID() changes the same way as for statements executed outside the body of these kinds of objects. The effect of a stored routine or trigger upon the value of LAST_INSERT_ID() that is seen by following statements depends on the kind of routine: o If a stored procedure executes statements that change the value of LAST_INSERT_ID(), the changed value will be seen by statements that follow the procedure call. o For stored functions and triggers that change the value, the value is restored when the function or trigger ends, so following statements will not see a changed value. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html?"LAST_DAYSyntax: LAST_DAY(date) Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns NULL if the argument is invalid. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT LAST_DAY('2003-02-05'); -> '2003-02-28' mysql> SELECT LAST_DAY('2004-02-05'); -> '2004-02-29' mysql> SELECT LAST_DAY('2004-01-01 01:01:01'); -> '2004-01-31' mysql> SELECT LAST_DAY('2003-03-32'); -> NULL Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html*2 MEDIUMINTMEDIUMINT[(M)] [UNSIGNED] [ZEROFILL] A medium-sized integer. The signed range is -8388608 to 8388607. The unsigned range is 0 to 16777215. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html8"FLOORSyntax: FLOOR(X) Returns the largest integer value not greater than X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Rmysql> SELECT FLOOR(1.23); -> 1 mysql> SELECT FLOOR(-1.23); -> -2 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"RTRIM$Syntax: RTRIM(str) Returns the string str with trailing space characters removed. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html 6mysql> SELECT RTRIM('barbar '); -> 'barbar' SELECT DEGREES(PI()); -> 180 mysql> SELECT DEGREES(PI() / 2); -> 90 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html{2VARCHAR)[NATIONAL] VARCHAR(M) [CHARACTER SET charset_name] [COLLATE collation_name] A variable-length string. M represents the maximum column length in characters. The range of M is 0 to 65,535. The effective maximum length of a VARCHAR is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used. For example, utf8 characters can require up to three bytes per character, so a VARCHAR column that uses the utf8 character set can be declared to be a maximum of 21,844 characters. MySQL stores VARCHAR values as a one-byte or two-byte length prefix plus data. The length prefix indicates the number of bytes in the value. A VARCHAR column uses one length byte if values require no more than 255 bytes, two length bytes if values may require more than 255 bytes. *Note*: MySQL 5.1 follows the standard SQL specification, and does not remove trailing spaces from VARCHAR values. VARCHAR is shorthand for CHARACTER VARYING. NATIONAL VARCHAR is the standard SQL way to define that a VARCHAR column should use some predefined character set. MySQL 4.1 and up uses utf8 as this predefined character set. http://dev.mysql.com/doc/refman/5.1/en/charset-national.html. NVARCHAR is shorthand for NATIONAL VARCHAR. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.htmlm"UNHEX$NSyntax: UNHEX(str) Performs the inverse operation of HEX(str). That is, it interprets each pair of hexadecimal digits in the argument as a number and converts it to the character represented by the number. The resulting characters are returned as a binary string. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT UNHEX('4D7953514C'); -> 'MySQL' mysql> SELECT 0x4D7953514C; -> 'MySQL' mysql> SELECT UNHEX(HEX('string')); -> 'string' mysql> SELECT HEX(UNHEX('1267')); -> '1267' SELECT - 2; -> -2 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html/" SELECT INTOSyntax: SELECT col_name [, col_name] ... INTO var_name [, var_name] ... table_expr SELECT ... INTO syntax enables selected columns to be stored directly into variables. The statement must retrieve only a single row. If it is possible that the statement may retrieve multiple rows, you can use LIMIT 1 to limit the result set to a single row. URL: http://dev.mysql.com/doc/refman/5.1/en/select-into-statement.html .SELECT id,data INTO x,y FROM test.t1 LIMIT 1; Ahttp://dev.mysql.com/doc/refman/5.1/en/select-into-statement.htmlv2STD*Syntax: STD(expr) Returns the population standard deviation of expr. This is an extension to standard SQL. The standard SQL function STDDEV_POP() can be used instead. This function returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html "COSSyntax: COS(X) Returns the cosine of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html 'mysql> SELECT COS(PI()); -> -1 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html?" DATE FUNCTIONSyntax: DATE(expr) Extracts the date part of the date or datetime expression expr. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Cmysql> SELECT DATE('2003-12-31 01:02:03'); -> '2003-12-31' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html=2 DROP TRIGGER&Syntax: DROP TRIGGER [IF EXISTS] [schema_name.]trigger_name This statement drops a trigger. The schema (database) name is optional. If the schema is omitted, the trigger is dropped from the default schema. DROP TRIGGER was added in MySQL 5.0.2. Its use requires the TRIGGER privilege for the table associated with the trigger. (This statement requires the SUPER privilege prior to MySQL 5.1.6.) Use IF EXISTS to prevent an error from occurring for a trigger that does not exist. A NOTE is generated for a non-existent trigger when using IF EXISTS. See [HELP SHOW WARNINGS]. The IF EXISTS clause was added in MySQL 5.1.14. Triggers for a table are also dropped if you drop the table. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-trigger.html 8http://dev.mysql.com/doc/refman/5.1/en/drop-trigger.htmlv2 RESET MASTER'Syntax: RESET MASTER Deletes all binary logs listed in the index file, resets the binary log index file to be empty, and creates a new binary log file. It is intended to be used only when the master is started for the first time. URL: http://dev.mysql.com/doc/refman/5.1/en/reset-master.html 8http://dev.mysql.com/doc/refman/5.1/en/reset-master.htmlR"TANSyntax: TAN(X) Returns the tangent of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html omysql> SELECT TAN(PI()); -> -1.2246063538224e-16 mysql> SELECT TAN(PI()+1); -> 1.5574077246549 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"PISyntax: PI() Returns the value of π (pi). The default number of decimal places displayed is seven, but MySQL uses the full double-precision value internally. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html qmysql> SELECT PI(); -> 3.141593 mysql> SELECT PI()+0.000000000000000000; -> 3.141592653589793116 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html" WEEKOFYEARSyntax: WEEKOFYEAR(date) Returns the calendar week of the date as a number in the range from 1 to 53. WEEKOFYEAR() is a compatibility function that is equivalent to WEEK(date,3). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 5mysql> SELECT WEEKOFYEAR('2008-02-20'); -> 8 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"/]Syntax: / Division: URL: http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html #mysql> SELECT 3/5; -> 0.60 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.htmlK"PURGE BINARY LOGSSyntax: PURGE { BINARY | MASTER } LOGS { TO 'log_name' | BEFORE datetime_expr } The binary log is a set of files that contain information about data modifications made by the MySQL server. The log consists of a set of binary log files, plus an index file. The PURGE BINARY LOGS statement deletes all the binary log files listed in the log index file prior to the specified log file name or date. The log files also are removed from the list recorded in the index file, so that the given log file becomes the first. This statement has no effect if the --log-bin option has not been enabled. URL: http://dev.mysql.com/doc/refman/5.1/en/purge-binary-logs.html VPURGE BINARY LOGS TO 'mysql-bin.010'; PURGE BINARY LOGS BEFORE '2008-04-02 22:46:26'; =http://dev.mysql.com/doc/refman/5.1/en/purge-binary-logs.html?2 STDDEV_SAMPSyntax: STDDEV_SAMP(expr) Returns the sample standard deviation of expr (the square root of VAR_SAMP(). STDDEV_SAMP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2SCHEMASyntax: SCHEMA() This function is a synonym for DATABASE(). URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.htmlQ2  MLINEFROMWKB MLineFromWKB(wkb[,srid]), MultiLineStringFromWKB(wkb[,srid]) Constructs a MULTILINESTRING value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions$" LOG2~Syntax: LOG2(X) Returns the base-2 logarithm of X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Smysql> SELECT LOG2(65536); -> 16 mysql> SELECT LOG2(-100); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html#" SUBTIMESyntax: SUBTIME(expr1,expr2) SUBTIME() returns expr1 - expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time expression. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002'); -> '2007-12-30 22:58:58.999997' mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998'); -> '-00:59:59.999999' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmln" UNCOMPRESSED_LENGTH Syntax: UNCOMPRESSED_LENGTH(compressed_string) Returns the length that the compressed string had before being compressed. URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html Kmysql> SELECT UNCOMPRESSED_LENGTH(COMPRESS(REPEAT('a',30))); -> 30 @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.htmlg2  DROP TABLE&Syntax: DROP [TEMPORARY] TABLE [IF EXISTS] tbl_name [, tbl_name] ... [RESTRICT | CASCADE] DROP TABLE removes one or more tables. You must have the DROP privilege for each table. All table data and the table definition are removed, so be careful with this statement! If any of the tables named in the argument list do not exist, MySQL returns an error indicating by name which non-existing tables it was unable to drop, but it also drops all of the tables in the list that do exist. *Important*: When a table is dropped, user privileges on the table are not automatically dropped. See [HELP GRANT]. Note that for a partitioned table, DROP TABLE permanently removes the table definition, all of its partitions, and all of the data which was stored in those partitions. It also removes the partitioning definition (.par) file associated with the dropped table. Use IF EXISTS to prevent an error from occurring for tables that do not exist. A NOTE is generated for each non-existent table when using IF EXISTS. See [HELP SHOW WARNINGS]. RESTRICT and CASCADE are allowed to make porting easier. In MySQL 5.1, they do nothing. *Note*: DROP TABLE automatically commits the current active transaction, unless you use the TEMPORARY keyword. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-table.html 6http://dev.mysql.com/doc/refman/5.1/en/drop-table.html-"POWSyntax: POW(X,Y) Returns the value of X raised to the power of Y. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Nmysql> SELECT POW(2,2); -> 4 mysql> SELECT POW(2,-2); -> 0.25 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"SHOW CREATE TABLESyntax: SHOW CREATE TABLE tbl_name Shows the CREATE TABLE statement that creates the given table. This statement also works with views. SHOW CREATE TABLE quotes table and column names according to the value of the SQL_QUOTE_SHOW_CREATE option. See http://dev.mysql.com/doc/refman/5.1/en/server-session-variables.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show-create-table.html mysql> SHOW CREATE TABLE t\G *************************** 1. row *************************** Table: t Create Table: CREATE TABLE t ( id INT(11) default NULL auto_increment, s char(60) default NULL, PRIMARY KEY (id) ) ENGINE=MyISAM =http://dev.mysql.com/doc/refman/5.1/en/show-create-table.html2DUALYou are allowed to specify DUAL as a dummy table name in situations where no tables are referenced: mysql> SELECT 1 + 1 FROM DUAL; -> 2 DUAL is purely for the convenience of people who require that all SELECT statements should have FROM and possibly other clauses. MySQL may ignore the clauses. MySQL does not require FROM DUAL if no tables are referenced. URL: http://dev.mysql.com/doc/refman/5.1/en/select.html 2http://dev.mysql.com/doc/refman/5.1/en/select.html"INSTR$Syntax: INSTR(str,substr) Returns the position of the first occurrence of substring substr in string str. This is the same as the two-argument form of LOCATE(), except that the order of the arguments is reversed. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html jmysql> SELECT INSTR('foobarbar', 'bar'); -> 4 mysql> SELECT INSTR('xbar', 'foobar'); -> 0 SELECT NOW(); -> '2007-12-15 23:50:26' mysql> SELECT NOW() + 0; -> 20071215235026.000000 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2 SHOW ENGINESMSyntax: SHOW [STORAGE] ENGINES SHOW ENGINES displays status information about the server's storage engines. This is particularly useful for checking whether a storage engine is supported, or to see what the default engine is. SHOW TABLE TYPES is a deprecated synonym. URL: http://dev.mysql.com/doc/refman/5.1/en/show-engines.html 8http://dev.mysql.com/doc/refman/5.1/en/show-engines.html">=kSyntax: >= Greater than or equal: URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html #mysql> SELECT 2 >= 2; -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"EXPSyntax: EXP(X) Returns the value of e (the base of natural logarithms) raised to the power of X. The inverse of this function is LOG() (using a single argument only) or LN(). URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT EXP(2); -> 7.3890560989307 mysql> SELECT EXP(-2); -> 0.13533528323661 mysql> SELECT EXP(0); -> 1 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2LONGBLOBLONGBLOB A BLOB column with a maximum length of 4,294,967,295 or 4GB (232 - 1) bytes. The effective maximum length of LONGBLOB columns depends on the configured maximum packet size in the client/server protocol and available memory. Each LONGBLOB value is stored using a four-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.htmls"POINTN PointN(ls,N) Returns the N-th Point in the Linestring value ls. Points are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions 'mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT AsText(PointN(GeomFromText(@ls),2)); +-------------------------------------+ | AsText(PointN(GeomFromText(@ls),2)) | +-------------------------------------+ | POINT(2 2) | +-------------------------------------+ ehttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions)2YEAR DATA TYPEYEAR[(2|4)] A year in two-digit or four-digit format. The default is four-digit format. In four-digit format, the allowable values are 1901 to 2155, and 0000. In two-digit format, the allowable values are 70 to 69, representing years from 1970 to 2069. MySQL displays YEAR values in YYYY format, but allows you to assign values to YEAR columns using either strings or numbers. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html Ghttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-type-overview.html2SUM;Syntax: SUM([DISTINCT] expr) Returns the sum of expr. If the return set has no rows, SUM() returns NULL. The DISTINCT keyword can be used in MySQL 5.1 to sum only the distinct values of expr. SUM() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlr"OCTSyntax: OCT(N) Returns a string representation of the octal value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,8). Returns NULL if N is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html 'mysql> SELECT OCT(12); -> '14' Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2SYSDATESyntax: SYSDATE() Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. SYSDATE() returns the time at which it executes. This differs from the behavior for NOW(), which returns a constant time that indicates the time at which the statement began to execute. (Within a stored routine or trigger, NOW() returns the time at which the routine or triggering statement began to execute.) mysql> SELECT NOW(), SLEEP(2), NOW(); +---------------------+----------+---------------------+ | NOW() | SLEEP(2) | NOW() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:36 | 0 | 2006-04-12 13:47:36 | +---------------------+----------+---------------------+ mysql> SELECT SYSDATE(), SLEEP(2), SYSDATE(); +---------------------+----------+---------------------+ | SYSDATE() | SLEEP(2) | SYSDATE() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:44 | 0 | 2006-04-12 13:47:46 | +---------------------+----------+---------------------+ In addition, the SET TIMESTAMP statement affects the value returned by NOW() but not by SYSDATE(). This means that timestamp settings in the binary log have no effect on invocations of SYSDATE(). Because SYSDATE() can return different values even within the same statement, and is not affected by SET TIMESTAMP, it is non-deterministic and therefore unsafe for replication if statement-based binary logging is used. If that is a problem, you can use row-based logging, or start the server with the --sysdate-is-now option to cause SYSDATE() to be an alias for NOW(). The non-deterministic nature of SYSDATE() also means that indexes cannot be used for evaluating expressions that refer to it. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2UNINSTALL PLUGINSyntax: UNINSTALL PLUGIN plugin_name This statement removes an installed plugin. You cannot uninstall a plugin if any table that uses it is open. plugin_name must be the name of some plugin that is listed in the mysql.plugin table. The server executes the plugin's deinitialization function and removes the row for the plugin from the mysql.plugin table, so that subsequent server restarts will not load and initialize the plugin. UNINSTALL PLUGIN does not remove the plugin's shared library file. To use UNINSTALL PLUGIN, you must have the DELETE privilege for the mysql.plugin table. URL: http://dev.mysql.com/doc/refman/5.1/en/uninstall-plugin.html SELECT REPEAT('MySQL', 3); -> 'MySQLMySQLMySQL' SELECT MAKEDATE(2011,31), MAKEDATE(2011,32); -> '2011-01-31', '2011-02-01' mysql> SELECT MAKEDATE(2011,365), MAKEDATE(2014,365); -> '2011-12-31', '2014-12-31' mysql> SELECT MAKEDATE(2011,0); -> NULL Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"!BINARY OPERATOR$Syntax: BINARY The BINARY operator casts the string following it to a binary string. This is an easy way to force a column comparison to be done byte by byte rather than character by character. This causes the comparison to be case sensitive even if the column isn't defined as BINARY or BLOB. BINARY also causes trailing spaces to be significant. URL: http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html mysql> SELECT 'a' = 'A'; -> 1 mysql> SELECT BINARY 'a' = 'A'; -> 0 mysql> SELECT 'a' = 'a '; -> 1 mysql> SELECT BINARY 'a' = 'a '; -> 0 :http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html2" MBROVERLAPSMBROverlaps(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 overlap. The term spatially overlaps is used if two geometries intersect and their intersection results in a geometry of the same dimension but not equal to either of the given geometries. URL: http://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html Ehttp://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html"#SOUNDEX$!Syntax: SOUNDEX(str) Returns a soundex string from str. Two strings that sound almost the same should have identical soundex strings. A standard soundex string is four characters long, but the SOUNDEX() function returns an arbitrarily long string. You can use SUBSTRING() on the result to get a standard soundex string. All non-alphabetic characters in str are ignored. All international alphabetic characters outside the A-Z range are treated as vowels. *Important*: When using SOUNDEX(), you should be aware of the following limitations: o This function, as currently implemented, is intended to work well with strings that are in the English language only. Strings in other languages may not produce reliable results. o This function is not guaranteed to provide consistent results with strings that use multi-byte character sets, including utf-8. We hope to remove these limitations in a future release. See Bug#22638 (http://bugs.mysql.com/22638) for more information. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html nmysql> SELECT SOUNDEX('Hello'); -> 'H400' mysql> SELECT SOUNDEX('Quadratically'); -> 'Q36324' 100; URL: http://dev.mysql.com/doc/refman/5.1/en/insert-select.html 9http://dev.mysql.com/doc/refman/5.1/en/insert-select.html{"'CREATE PROCEDURE&Syntax: CREATE [DEFINER = { user | CURRENT_USER }] PROCEDURE sp_name ([proc_parameter[,...]]) [characteristic ...] routine_body CREATE [DEFINER = { user | CURRENT_USER }] FUNCTION sp_name ([func_parameter[,...]]) RETURNS type [characteristic ...] routine_body proc_parameter: [ IN | OUT | INOUT ] param_name type func_parameter: param_name type type: Any valid MySQL data type characteristic: LANGUAGE SQL | [NOT] DETERMINISTIC | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } | COMMENT 'string' routine_body: Valid SQL procedure statement These statements create stored routines. By default, a routine is associated with the default database. To associate the routine explicitly with a given database, specify the name as db_name.sp_name when you create it. The CREATE FUNCTION statement is also used in MySQL to support UDFs (user-defined functions). See http://dev.mysql.com/doc/refman/5.1/en/adding-functions.html. A UDF can be regarded as an external stored function. However, do note that stored functions share their namespace with UDFs. See http://dev.mysql.com/doc/refman/5.1/en/function-resolution.html, for the rules describing how the server interprets references to different kinds of functions. When the routine is invoked, an implicit USE db_name is performed (and undone when the routine terminates). The causes the routine to have the given default database while it executes. USE statements within stored routines are disallowed. When a stored function has been created, you invoke it by referring to it in an expression. The function returns a value during expression evaluation. When a stored procedure has been created, you invoke it by using the CALL statement (see [HELP CALL]). To execute the CREATE PROCEDURE or CREATE FUNCTION statement, it is necessary to have the CREATE ROUTINE privilege. By default, MySQL automatically grants the ALTER ROUTINE and EXECUTE privileges to the routine creator. See also http://dev.mysql.com/doc/refman/5.1/en/stored-routines-privileges.html. If binary logging is enabled, the CREATE FUNCTION statement might also require the SUPER privilege, as described in http://dev.mysql.com/doc/refman/5.1/en/stored-programs-logging.html. The DEFINER and SQL SECURITY clauses specify the security context to be used when checking access privileges at routine execution time, as described later. If the routine name is the same as the name of a built-in SQL function, you must use a space between the name and the following parenthesis when defining the routine, or a syntax error occurs. This is also true when you invoke the routine later. For this reason, we suggest that it is better to avoid re-using the names of existing SQL functions for your own stored routines. The IGNORE_SPACE SQL mode applies to built-in functions, not to stored routines. It is always allowable to have spaces after a routine name, regardless of whether IGNORE_SPACE is enabled. The parameter list enclosed within parentheses must always be present. If there are no parameters, an empty parameter list of () should be used. Parameter names are not case sensitive. Each parameter can be declared to use any valid data type, except that the COLLATE attribute cannot be used. Each parameter is an IN parameter by default. To specify otherwise for a parameter, use the keyword OUT or INOUT before the parameter name. *Note*: Specifying a parameter as IN, OUT, or INOUT is valid only for a PROCEDURE. (FUNCTION parameters are always regarded as IN parameters.) An IN parameter passes a value into a procedure. The procedure might modify the value, but the modification is not visible to the caller when the procedure returns. An OUT parameter passes a value from the procedure back to the caller. Its initial value is NULL within the procedure, and its value is visible to the caller when the procedure returns. An INOUT parameter is initialized by the caller, can be modified by the procedure, and any change made by the procedure is visible to the caller when the procedure returns. For each OUT or INOUT parameter, pass a user-defined variable so that you can obtain its value when the procedure returns. (For an example, see [HELP CALL].) If you are calling the procedure from within another stored procedure or function, you can also pass a routine parameter or local routine variable as an IN or INOUT parameter. The RETURNS clause may be specified only for a FUNCTION, for which it is mandatory. It indicates the return type of the function, and the function body must contain a RETURN value statement. If the RETURN statement returns a value of a different type, the value is coerced to the proper type. For example, if a function specifies an ENUM or SET value in the RETURNS clause, but the RETURN statement returns an integer, the value returned from the function is the string for the corresponding ENUM member of set of SET members. The routine_body consists of a valid SQL procedure statement. This can be a simple statement such as SELECT or INSERT, or it can be a compound statement written using BEGIN and END. Compound statements can contain declarations, loops, and other control structure statements. The syntax for these statements is described in http://dev.mysql.com/doc/refman/5.1/en/sql-syntax-compound-statements.h tml. Some statements are not allowed in stored routines; see http://dev.mysql.com/doc/refman/5.1/en/stored-program-restrictions.html . MySQL stores the sql_mode system variable setting that is in effect at the time a routine is created, and always executes the routine with this setting in force, regardless of the current server SQL mode. URL: http://dev.mysql.com/doc/refman/5.1/en/create-procedure.html lmysql> delimiter // mysql> CREATE PROCEDURE simpleproc (OUT param1 INT) -> BEGIN -> SELECT COUNT(*) INTO param1 FROM t; -> END; -> // Query OK, 0 rows affected (0.00 sec) mysql> delimiter ; mysql> CALL simpleproc(@a); Query OK, 0 rows affected (0.00 sec) mysql> SELECT @a; +------+ | @a | +------+ | 3 | +------+ 1 row in set (0.00 sec) SELECT TO_DAYS(950501); -> 728779 mysql> SELECT TO_DAYS('2007-10-07'); -> 733321 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2, NOT REGEXP$Syntax: expr NOT REGEXP pat, expr NOT RLIKE pat This is the same as NOT (expr REGEXP pat). URL: http://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html Ghttp://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.htmlZ2- SHOW INDEXSyntax: SHOW INDEX FROM tbl_name [FROM db_name] SHOW INDEX returns table index information. The format resembles that of the SQLStatistics call in ODBC. You can use db_name.tbl_name as an alternative to the tbl_name FROM db_name syntax. These two statements are equivalent: SHOW INDEX FROM mytable FROM mydb; SHOW INDEX FROM mydb.mytable; SHOW KEYS is a synonym for SHOW INDEX. You can also list a table's indexes with the mysqlshow -k db_name tbl_name command. URL: http://dev.mysql.com/doc/refman/5.1/en/show-index.html 6http://dev.mysql.com/doc/refman/5.1/en/show-index.html ".SHOW CREATE DATABASESyntax: SHOW CREATE {DATABASE | SCHEMA} db_name Shows the CREATE DATABASE statement that creates the given database. SHOW CREATE SCHEMA is a synonym for SHOW CREATE DATABASE. URL: http://dev.mysql.com/doc/refman/5.1/en/show-create-database.html mysql> SHOW CREATE DATABASE test\G *************************** 1. row *************************** Database: test Create Database: CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ mysql> SHOW CREATE SCHEMA test\G *************************** 1. row *************************** Database: test Create Database: CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ @http://dev.mysql.com/doc/refman/5.1/en/show-create-database.htmlE2/LEAVESyntax: LEAVE label This statement is used to exit the flow control construct that has the given label. It can be used within BEGIN ... END or loop constructs (LOOP, REPEAT, WHILE). URL: http://dev.mysql.com/doc/refman/5.1/en/leave-statement.html ;http://dev.mysql.com/doc/refman/5.1/en/leave-statement.html20NOT INSyntax: expr NOT IN (value,...) This is the same as NOT (expr IN (value,...)). URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"1! Syntax: NOT, ! Logical NOT. Evaluates to 1 if the operand is 0, to 0 if the operand is non-zero, and NOT NULL returns NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/logical-operators.html mysql> SELECT NOT 10; -> 0 mysql> SELECT NOT 0; -> 1 mysql> SELECT NOT NULL; -> NULL mysql> SELECT ! (1+1); -> 0 mysql> SELECT ! 1+1; -> 1 =http://dev.mysql.com/doc/refman/5.1/en/logical-operators.html "2DECLARE HANDLERSyntax: DECLARE handler_type HANDLER FOR condition_value [, condition_value] ... statement handler_type: CONTINUE | EXIT | UNDO condition_value: SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION | mysql_error_code The DECLARE ... HANDLER statement specifies handlers that each may deal with one or more conditions. If one of these conditions occurs, the specified statement is executed. statement can be a simple statement (for example, SET var_name = value), or it can be a compound statement written using BEGIN and END (see [HELP BEGIN END]). For a CONTINUE handler, execution of the current program continues after execution of the handler statement. For an EXIT handler, execution terminates for the BEGIN ... END compound statement in which the handler is declared. (This is true even if the condition occurs in an inner block.) The UNDO handler type statement is not supported. If a condition occurs for which no handler has been declared, the default action is EXIT. A condition_value for DECLARE ... HANDLER can be any of the following values: o An SQLSTATE value (a 5-character string literal) or a MySQL error code (a number). You should not use SQLSTATE value '00000' or MySQL error code 0, because those indicate sucess rather than an error condition. For a list of SQLSTATE values and MySQL error codes, see http://dev.mysql.com/doc/refman/5.1/en/error-messages-server.html. o A condition name previously specified with DECLARE ... CONDITION. See [HELP DECLARE CONDITION]. o SQLWARNING is shorthand for the class of SQLSTATE values that begin with '01'. o NOT FOUND is shorthand for the class of SQLSTATE values that begin with '02'. This is relevant only within the context of cursors and is used to control what happens when a cursor reaches the end of a data set. o SQLEXCEPTION is shorthand for the class of SQLSTATE values that do not begin with '00', '01', or '02'. URL: http://dev.mysql.com/doc/refman/5.1/en/declare-handlers.html gmysql> CREATE TABLE test.t (s1 INT, PRIMARY KEY (s1)); Query OK, 0 rows affected (0.00 sec) mysql> delimiter // mysql> CREATE PROCEDURE handlerdemo () -> BEGIN -> DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET @x2 = 1; -> SET @x = 1; -> INSERT INTO test.t VALUES (1); -> SET @x = 2; -> INSERT INTO test.t VALUES (1); -> SET @x = 3; -> END; -> // Query OK, 0 rows affected (0.00 sec) mysql> CALL handlerdemo()// Query OK, 0 rows affected (0.00 sec) mysql> SELECT @x// +------+ | @x | +------+ | 3 | +------+ 1 row in set (0.00 sec) SELECT 1 && 1; -> 1 mysql> SELECT 1 && 0; -> 0 mysql> SELECT 1 && NULL; -> NULL mysql> SELECT 0 && NULL; -> 0 mysql> SELECT NULL && 0; -> 0 =http://dev.mysql.com/doc/refman/5.1/en/logical-operators.html"6X X(p) Returns the X-coordinate value for the point p as a double-precision number. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#point-property-functions mysql> SET @pt = 'Point(56.7 53.34)'; mysql> SELECT X(GeomFromText(@pt)); +----------------------+ | X(GeomFromText(@pt)) | +----------------------+ | 56.7 | +----------------------+ `http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#point-property-functions"7 FOUND_ROWSSyntax: FOUND_ROWS() A SELECT statement may include a LIMIT clause to restrict the number of rows the server returns to the client. In some cases, it is desirable to know how many rows the statement would have returned without the LIMIT, but without running the statement again. To obtain this row count, include a SQL_CALC_FOUND_ROWS option in the SELECT statement, and then invoke FOUND_ROWS() afterward: URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html nmysql> SELECT SQL_CALC_FOUND_ROWS * FROM tbl_name -> WHERE id > 100 LIMIT 10; mysql> SELECT FOUND_ROWS(); Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html28 SYSTEM_USERSyntax: SYSTEM_USER() SYSTEM_USER() is a synonym for USER(). URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html29CROSSESCrosses(g1,g2) Returns 1 if g1 spatially crosses g2. Returns NULL if g1 is a Polygon or a MultiPolygon, or if g2 is a Point or a MultiPoint. Otherwise, returns 0. The term spatially crosses denotes a spatial relation between two given geometries that has the following properties: o The two geometries intersect o Their intersection results in a geometry that has a dimension that is one less than the maximum dimension of the two given geometries o Their intersection is not equal to either of the two given geometries URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html 2:TRUNCATE TABLE6 Syntax: TRUNCATE [TABLE] tbl_name TRUNCATE TABLE empties a table completely. Logically, this is equivalent to a DELETE statement that deletes all rows, but there are practical differences under some circumstances. For an InnoDB table, InnoDB processes TRUNCATE TABLE by deleting rows one by one if there are any FOREIGN KEY constraints that reference the table. If there are no FOREIGN KEY constraints, InnoDB performs fast truncation by dropping the original table and creating an empty one with the same definition, which is much faster than deleting rows one by one. The AUTO_INCREMENT counter is reset by TRUNCATE TABLE, regardless of whether there is a FOREIGN KEY constraint. In the case that FOREIGN KEY constraints reference the table, InnoDB deletes rows one by one and processes the constraints on each one. If the FOREIGN KEY constraint specifies DELETE CASCADE, rows from the child (referenced) table are deleted, and the truncated table becomes empty. If the FOREIGN KEY constraint does not specify CASCADE, the TRUNCATE statement deletes rows one by one and stops if it encounters a parent row that is referenced by the child, returning this error: ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails (`test`.`child`, CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`id`)) This is the same as a DELETE statement with no WHERE clause. The count of rows affected by TRUNCATE TABLE is accurate only when it is mapped to a DELETE statement. For other storage engines, TRUNCATE TABLE differs from DELETE in the following ways in MySQL 5.1: o Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly for large tables. o Truncate operations are not transaction-safe; an error occurs when attempting one in the course of an active transaction or active table lock. o Truncation operations do not return the number of deleted rows. o As long as the table format file tbl_name.frm is valid, the table can be re-created as an empty table with TRUNCATE TABLE, even if the data or index files have become corrupted. o The table handler does not remember the last used AUTO_INCREMENT value, but starts counting from the beginning. This is true even for MyISAM and InnoDB, which normally do not reuse sequence values. o When used with partitioned tables, TRUNCATE TABLE preserves the partitioning; that is, the data and index files are dropped and re-created, while the partition definitions (.par) file is unaffected. o Since truncation of a table does not make any use of DELETE, the TRUNCATE statement does not invoke ON DELETE triggers. TRUNCATE TABLE requires the DROP privilege as of MySQL 5.1.16. (Before 5.1.16, it requires the DELETE privilege. URL: http://dev.mysql.com/doc/refman/5.1/en/truncate.html 4http://dev.mysql.com/doc/refman/5.1/en/truncate.html2;BIT_XORSyntax: BIT_XOR(expr) Returns the bitwise XOR of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2< CURRENT_DATESyntax: CURRENT_DATE, CURRENT_DATE() CURRENT_DATE and CURRENT_DATE() are synonyms for CURDATE(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2= START SLAVE?Syntax: START SLAVE [thread_type [, thread_type] ... ] START SLAVE [SQL_THREAD] UNTIL MASTER_LOG_FILE = 'log_name', MASTER_LOG_POS = log_pos START SLAVE [SQL_THREAD] UNTIL RELAY_LOG_FILE = 'log_name', RELAY_LOG_POS = log_pos thread_type: IO_THREAD | SQL_THREAD START SLAVE with no thread_type options starts both of the slave threads. The I/O thread reads queries from the master server and stores them in the relay log. The SQL thread reads the relay log and executes the queries. START SLAVE requires the SUPER privilege. If START SLAVE succeeds in starting the slave threads, it returns without any error. However, even in that case, it might be that the slave threads start and then later stop (for example, because they do not manage to connect to the master or read its binary logs, or some other problem). START SLAVE does not warn you about this. You must check the slave's error log for error messages generated by the slave threads, or check that they are running satisfactorily with SHOW SLAVE STATUS. URL: http://dev.mysql.com/doc/refman/5.1/en/start-slave.html 7http://dev.mysql.com/doc/refman/5.1/en/start-slave.htmla">AREAArea(poly) Returns as a double-precision number the area of the Polygon value poly, as measured in its spatial reference system. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functions mysql> SET @poly = 'Polygon((0 0,0 3,3 0,0 0),(1 1,1 2,2 1,1 1))'; mysql> SELECT Area(GeomFromText(@poly)); +---------------------------+ | Area(GeomFromText(@poly)) | +---------------------------+ | 4 | +---------------------------+ bhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functionsz2? BEGIN END1Syntax: [begin_label:] BEGIN [statement_list] END [end_label] BEGIN ... END syntax is used for writing compound statements, which can appear within stored programs. A compound statement can contain multiple statements, enclosed by the BEGIN and END keywords. statement_list represents a list of one or more statements, each terminated by a semicolon (;) statement delimiter. statement_list is optional, which means that the empty compound statement (BEGIN END) is legal. Use of multiple statements requires that a client is able to send statement strings containing the ; statement delimiter. This is handled in the mysql command-line client with the delimiter command. Changing the ; end-of-statement delimiter (for example, to //) allows ; to be used in a program body. For an example, see http://dev.mysql.com/doc/refman/5.1/en/stored-programs-defining.html. A compound statement can be labeled. end_label cannot be given unless begin_label also is present. If both are present, they must be the same. URL: http://dev.mysql.com/doc/refman/5.1/en/begin-end.html 5http://dev.mysql.com/doc/refman/5.1/en/begin-end.html2@FLUSHJSyntax: FLUSH [LOCAL | NO_WRITE_TO_BINLOG] flush_option [, flush_option] ... The FLUSH statement clears or reloads various internal caches used by MySQL. To execute FLUSH, you must have the RELOAD privilege. The RESET statement is similar to FLUSH. See [HELP RESET]. URL: http://dev.mysql.com/doc/refman/5.1/en/flush.html 1http://dev.mysql.com/doc/refman/5.1/en/flush.html}"ASHOW PROCEDURE STATUS<Syntax: SHOW {PROCEDURE | FUNCTION} STATUS [LIKE 'pattern' | WHERE expr] These statements are MySQL extensions. They return characteristics of routines, such as the database, name, type, creator, creation and modification dates, and character set information. The LIKE clause, if present, indicates which procedure or function names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show-procedure-status.html mysql> SHOW FUNCTION STATUS LIKE 'hello'\G *************************** 1. row *************************** Db: test Name: hello Type: FUNCTION Definer: testuser@localhost Modified: 2004-08-03 15:29:37 Created: 2004-08-03 15:29:37 Security_type: DEFINER Comment: character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci Ahttp://dev.mysql.com/doc/refman/5.1/en/show-procedure-status.html2B SHOW WARNINGSSyntax: SHOW WARNINGS [LIMIT [offset,] row_count] SHOW COUNT(*) WARNINGS SHOW WARNINGS shows the error, warning, and note messages that resulted from the last statement that generated messages. It shows nothing if the last statement used a table and generated no messages. (That is, a statement that uses a table but generates no messages clears the message list.) Statements that do not use tables and do not generate messages have no effect on the message list. A related statement, SHOW ERRORS, shows only the errors. See [HELP SHOW ERRORS]. The SHOW COUNT(*) WARNINGS statement displays the total number of errors, warnings, and notes. You can also retrieve this number from the warning_count variable: SHOW COUNT(*) WARNINGS; SELECT @@warning_count; The value of warning_count might be greater than the number of messages displayed by SHOW WARNINGS if the max_error_count system variable is set so low that not all messages are stored. An example shown later in this section demonstrates how this can happen. The LIMIT clause has the same syntax as for the SELECT statement. See http://dev.mysql.com/doc/refman/5.1/en/select.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show-warnings.html 9http://dev.mysql.com/doc/refman/5.1/en/show-warnings.htmlp2CDESCRIBE)Syntax: {DESCRIBE | DESC} tbl_name [col_name | wild] DESCRIBE provides information about the columns in a table. It is a shortcut for SHOW COLUMNS FROM. These statements also display information for views. (See [HELP SHOW COLUMNS].) col_name can be a column name, or a string containing the SQL "%" and "_" wildcard characters to obtain output only for the columns with names matching the string. There is no need to enclose the string within quotes unless it contains spaces or other special characters. mysql> DESCRIBE City; +------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+----------+------+-----+---------+----------------+ | Id | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | Country | char(3) | NO | UNI | | | | District | char(20) | YES | MUL | | | | Population | int(11) | NO | | 0 | | +------------+----------+------+-----+---------+----------------+ 5 rows in set (0.00 sec) The description for SHOW COLUMNS provides more information about the output columns (see [HELP SHOW COLUMNS]). URL: http://dev.mysql.com/doc/refman/5.1/en/describe.html 4http://dev.mysql.com/doc/refman/5.1/en/describe.html 2D DROP USER Syntax: DROP USER user [, user] ... The DROP USER statement removes one or more MySQL accounts. It removes privilege rows for the account from all grant tables. To use this statement, you must have the global CREATE USER privilege or the DELETE privilege for the mysql database. Each account is named using the same format as for the GRANT statement; for example, 'jeffrey'@'localhost'. If you specify only the username part of the account name, a hostname part of '%' is used. For additional information about specifying account names, see [HELP GRANT]. With DROP USER, you can remove an account and its privileges as follows: DROP USER user; URL: http://dev.mysql.com/doc/refman/5.1/en/drop-user.html 5http://dev.mysql.com/doc/refman/5.1/en/drop-user.html2E STDDEV_POP<Syntax: STDDEV_POP(expr) Returns the population standard deviation of expr (the square root of VAR_POP()). You can also use STD() or STDDEV(), which are equivalent but not standard SQL. STDDEV_POP() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlu2FSHOW CHARACTER SETSyntax: SHOW CHARACTER SET [LIKE 'pattern' | WHERE expr] The SHOW CHARACTER SET statement shows all available character sets. The LIKE clause, if present, indicates which character set names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. For example: mysql> SHOW CHARACTER SET LIKE 'latin%'; +---------+-----------------------------+-------------------+--------+ | Charset | Description | Default collation | Maxlen | +---------+-----------------------------+-------------------+--------+ | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 | | latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 | +---------+-----------------------------+-------------------+--------+ URL: http://dev.mysql.com/doc/refman/5.1/en/show-character-set.html >http://dev.mysql.com/doc/refman/5.1/en/show-character-set.html"G SUBSTRING$6Syntax: SUBSTRING(str,pos), SUBSTRING(str FROM pos), SUBSTRING(str,pos,len), SUBSTRING(str FROM pos FOR len) The forms without a len argument return a substring from string str starting at position pos. The forms with a len argument return a substring len characters long from string str, starting at position pos. The forms that use FROM are standard SQL syntax. It is also possible to use a negative value for pos. In this case, the beginning of the substring is pos characters from the end of the string, rather than the beginning. A negative value may be used for pos in any of the forms of this function. For all forms of SUBSTRING(), the position of the first character in the string from which the substring is to be extracted is reckoned as 1. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT SUBSTRING('Quadratically',5); -> 'ratically' mysql> SELECT SUBSTRING('foobarbar' FROM 4); -> 'barbar' mysql> SELECT SUBSTRING('Quadratically',5,6); -> 'ratica' mysql> SELECT SUBSTRING('Sakila', -3); -> 'ila' mysql> SELECT SUBSTRING('Sakila', -5, 3); -> 'aki' mysql> SELECT SUBSTRING('Sakila' FROM -4 FOR 2); -> 'ki' SELECT LTRIM(' barbar'); -> 'barbar' INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6) -> ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b); Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"NSUBSTRING_INDEX$Syntax: SUBSTRING_INDEX(str,delim,count) Returns the substring from string str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned. SUBSTRING_INDEX() performs a case-sensitive match when searching for delim. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT SUBSTRING_INDEX('www.mysql.com', '.', 2); -> 'www.mysql' mysql> SELECT SUBSTRING_INDEX('www.mysql.com', '.', -2); -> 'mysql.com' SELECT TRUNCATE(1.223,1); -> 1.2 mysql> SELECT TRUNCATE(1.999,1); -> 1.9 mysql> SELECT TRUNCATE(1.999,0); -> 1 mysql> SELECT TRUNCATE(-1.999,1); -> -1.9 mysql> SELECT TRUNCATE(122,-2); -> 100 mysql> SELECT TRUNCATE(10.28*100,0); -> 1028 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"R TIMESTAMPADDSyntax: TIMESTAMPADD(unit,interval,datetime_expr) Adds the integer expression interval to the date or datetime expression datetime_expr. The unit for interval is given by the unit argument, which should be one of the following values: FRAC_SECOND (microseconds), SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR. Beginning with MySQL 5.1.24, it is possible to use MICROSECOND in place of FRAC_SECOND with this function, and FRAC_SECOND is deprecated. The unit value may be specified using one of keywords as shown, or with a prefix of SQL_TSI_. For example, DAY and SQL_TSI_DAY both are legal. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT TIMESTAMPADD(MINUTE,1,'2003-01-02'); -> '2003-01-02 00:01:00' mysql> SELECT TIMESTAMPADD(WEEK,1,'2003-01-02'); -> '2003-01-09' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2SSHOWWSHOW has many forms that provide information about databases, tables, columns, or status information about the server. This section describes those following: SHOW AUTHORS SHOW CHARACTER SET [like_or_where] SHOW COLLATION [like_or_where] SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where] SHOW CONTRIBUTORS SHOW CREATE DATABASE db_name SHOW CREATE EVENT event_name SHOW CREATE FUNCTION funcname SHOW CREATE PROCEDURE procname SHOW CREATE TABLE tbl_name SHOW CREATE TRIGGER trigger_name SHOW CREATE VIEW view_name SHOW DATABASES [like_or_where] SHOW ENGINE engine_name {STATUS | MUTEX} SHOW [STORAGE] ENGINES SHOW ERRORS [LIMIT [offset,] row_count] SHOW [FULL] EVENTS SHOW FUNCTION CODE sp_name SHOW FUNCTION STATUS [like_or_where] SHOW GRANTS FOR user SHOW INDEX FROM tbl_name [FROM db_name] SHOW INNODB STATUS SHOW OPEN TABLES [FROM db_name] [like_or_where] SHOW PLUGINS SHOW PROCEDURE CODE sp_name SHOW PROCEDURE STATUS [like_or_where] SHOW PRIVILEGES SHOW [FULL] PROCESSLIST SHOW PROFILE [types] [FOR QUERY n] [OFFSET n] [LIMIT n] SHOW PROFILES SHOW SCHEDULER STATUS SHOW [GLOBAL | SESSION] STATUS [like_or_where] SHOW TABLE STATUS [FROM db_name] [like_or_where] SHOW TABLES [FROM db_name] [like_or_where] SHOW TRIGGERS [FROM db_name] [like_or_where] SHOW [GLOBAL | SESSION] VARIABLES [like_or_where] SHOW WARNINGS [LIMIT [offset,] row_count] like_or_where: LIKE 'pattern' | WHERE expr If the syntax for a given SHOW statement includes a LIKE 'pattern' part, 'pattern' is a string that can contain the SQL "%" and "_" wildcard characters. The pattern is useful for restricting statement output to matching values. Several SHOW statements also accept a WHERE clause that provides more flexibility in specifying which rows to display. See http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.1/en/show.html 0http://dev.mysql.com/doc/refman/5.1/en/show.html"TGREATESTSyntax: GREATEST(value1,value2,...) With two or more arguments, returns the largest (maximum-valued) argument. The arguments are compared using the same rules as for LEAST(). URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html mysql> SELECT GREATEST(2,0); -> 2 mysql> SELECT GREATEST(34.0,3.0,5.0,767.0); -> 767.0 mysql> SELECT GREATEST('B','A','C'); -> 'C' @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html 2USHOW VARIABLESSyntax: SHOW [GLOBAL | SESSION] VARIABLES [LIKE 'pattern' | WHERE expr] SHOW VARIABLES shows the values of MySQL system variables. This information also can be obtained using the mysqladmin variables command. The LIKE clause, if present, indicates which variable names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. With the GLOBAL modifier, SHOW VARIABLES displays the values that are used for new connections to MySQL. With SESSION, it displays the values that are in effect for the current connection. If no modifier is present, the default is SESSION. LOCAL is a synonym for SESSION. With a LIKE clause, the statement displays only rows for those variables with names that match the pattern. To obtain the row for a specific variable, use a LIKE clause as shown: SHOW VARIABLES LIKE 'max_join_size'; SHOW SESSION VARIABLES LIKE 'max_join_size'; To get a list of variables whose name match a pattern, use the "%" wildcard character in a LIKE clause: SHOW VARIABLES LIKE '%size%'; SHOW GLOBAL VARIABLES LIKE '%size%'; Wildcard characters can be used in any position within the pattern to be matched. Strictly speaking, because "_" is a wildcard that matches any single character, you should escape it as "\_" to match it literally. In practice, this is rarely necessary. URL: http://dev.mysql.com/doc/refman/5.1/en/show-variables.html :http://dev.mysql.com/doc/refman/5.1/en/show-variables.html:2VBINLOGSyntax: BINLOG 'str' BINLOG is an internal-use statement. It is generated by the mysqlbinlog program as the printable representation of certain events in binary log files. (See http://dev.mysql.com/doc/refman/5.1/en/mysqlbinlog.html.) The 'str' value is a base 64-encoded string the that server decodes to determine the data change indicated by the corresponding event. This statement requires the SUPER privilege. It was added in MySQL 5.1.5. URL: http://dev.mysql.com/doc/refman/5.1/en/binlog.html 2http://dev.mysql.com/doc/refman/5.1/en/binlog.html2WBIT_ANDSyntax: BIT_AND(expr) Returns the bitwise AND of all bits in expr. The calculation is performed with 64-bit (BIGINT) precision. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html"XSECONDSyntax: SECOND(time) Returns the second for time, in the range 0 to 59. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html /mysql> SELECT SECOND('10:05:03'); -> 3 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"YATAN20Syntax: ATAN(Y,X), ATAN2(Y,X) Returns the arc tangent of the two variables X and Y. It is similar to calculating the arc tangent of Y / X, except that the signs of both arguments are used to determine the quadrant of the result. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html omysql> SELECT ATAN(-2,2); -> -0.78539816339745 mysql> SELECT ATAN2(PI(),0); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"Z MBRCONTAINS MBRContains(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangle of g1 contains the Minimum Bounding Rectangle of g2. This tests the opposite relationship as MBRWithin(). URL: http://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html mysql> SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); mysql> SET @g2 = GeomFromText('Point(1 1)'); mysql> SELECT MBRContains(@g1,@g2), MBRContains(@g2,@g1); ----------------------+----------------------+ | MBRContains(@g1,@g2) | MBRContains(@g2,@g1) | +----------------------+----------------------+ | 1 | 0 | +----------------------+----------------------+ Ehttp://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html"[HOUR!Syntax: HOUR(time) Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of TIME values actually is much larger, so HOUR can return values greater than 23. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html ^mysql> SELECT HOUR('10:05:03'); -> 10 mysql> SELECT HOUR('272:59:59'); -> 272 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlV2\SELECTSyntax: SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr, ... [FROM table_references [WHERE where_condition] [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr | position} [ASC | DESC], ...] [LIMIT {[offset,] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name(argument_list)] [INTO OUTFILE 'file_name' export_options | INTO DUMPFILE 'file_name' | INTO var_name [, var_name]] [FOR UPDATE | LOCK IN SHARE MODE]] SELECT is used to retrieve rows selected from one or more tables, and can include UNION statements and subqueries. See [HELP UNION], and http://dev.mysql.com/doc/refman/5.1/en/subqueries.html. The most commonly used clauses of SELECT statements are these: o Each select_expr indicates a column that you want to retrieve. There must be at least one select_expr. o table_references indicates the table or tables from which to retrieve rows. Its syntax is described in [HELP JOIN]. o The WHERE clause, if given, indicates the condition or conditions that rows must satisfy to be selected. where_condition is an expression that evaluates to true for each row to be selected. The statement selects all rows if there is no WHERE clause. In the WHERE clause, you can use any of the functions and operators that MySQL supports, except for aggregate (summary) functions. See http://dev.mysql.com/doc/refman/5.1/en/functions.html. SELECT can also be used to retrieve rows computed without reference to any table. URL: http://dev.mysql.com/doc/refman/5.1/en/select.html 2http://dev.mysql.com/doc/refman/5.1/en/select.html!"]COTvSyntax: COT(X) Returns the cotangent of X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Ymysql> SELECT COT(12); -> -1.5726734063977 mysql> SELECT COT(0); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlq"^SHOW CREATE EVENTASyntax: SHOW CREATE EVENT event_name This statement displays the CREATE EVENT statement needed to re-create a given event. For example (using the same event e_daily defined and then altered in http://dev.mysql.com/doc/refman/5.1/en/show-events.html): URL: http://dev.mysql.com/doc/refman/5.1/en/show-create-event.html mysql> SHOW CREATE EVENT test.e_daily\G *************************** 1. row *************************** Event: e_daily sql_mode: time_zone: SYSTEM Create Event: CREATE EVENT `e_daily` ON SCHEDULE EVERY 1 DAY STARTS CURRENT_TIMESTAMP + INTERVAL 6 HOUR ON COMPLETION NOT PRESERVE ENABLE COMMENT 'Saves total number of sessions then clears the table each day' DO BEGIN INSERT INTO site_activity.totals (time, total) SELECT CURRENT_TIMESTAMP, COUNT(*) FROM site_activity.sessions; DELETE FROM site_activity.sessions; END character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci =http://dev.mysql.com/doc/refman/5.1/en/show-create-event.html.2_ BACKUP TABLESyntax: BACKUP TABLE tbl_name [, tbl_name] ... TO '/path/to/backup/directory' *Note*: This statement is deprecated. We are working on a better replacement for it that will provide online backup capabilities. In the meantime, the mysqlhotcopy script can be used instead. BACKUP TABLE copies to the backup directory the minimum number of table files needed to restore the table, after flushing any buffered changes to disk. The statement works only for MyISAM tables. It copies the .frm definition and .MYD data files. The .MYI index file can be rebuilt from those two files. The directory should be specified as a full pathname. To restore the table, use RESTORE TABLE. URL: http://dev.mysql.com/doc/refman/5.1/en/backup-table.html 8http://dev.mysql.com/doc/refman/5.1/en/backup-table.html@"` LOAD_FILE$Syntax: LOAD_FILE(file_name) Reads the file and returns the file contents as a string. To use this function, the file must be located on the server host, you must specify the full pathname to the file, and you must have the FILE privilege. The file must be readable by all and its size less than max_allowed_packet bytes. If the file does not exist or cannot be read because one of the preceding conditions is not satisfied, the function returns NULL. As of MySQL 5.1.6, the character_set_filesystem system variable controls interpretation of filenames that are given as literal strings. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html [mysql> UPDATE t SET blob_col=LOAD_FILE('/tmp/picture') WHERE id=1; SELECT student_name, -> GROUP_CONCAT(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlP"d DATE_FORMATSyntax: DATE_FORMAT(date,format) Formats the date value according to the format string. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Qmysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y'); -> 'Sunday October 2009' mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s'); -> '22:23:00' mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00', -> '%D %y %a %d %m %b %j'); -> '4th 00 Thu 04 10 Oct 277' mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00', -> '%H %k %I %r %T %S %w'); -> '22 22 10 10:23:00 PM 22:23:00 00 6' mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V'); -> '1998 52' mysql> SELECT DATE_FORMAT('2006-06-00', '%d'); -> '00' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"e BENCHMARKnSyntax: BENCHMARK(count,expr) The BENCHMARK() function executes the expression expr repeatedly count times. It may be used to time how quickly MySQL processes the expression. The result value is always 0. The intended use is from within the mysql client, which reports query execution times: URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html Imysql> SELECT BENCHMARK(1000000,ENCODE('hello','goodbye')); +----------------------------------------------+ | BENCHMARK(1000000,ENCODE('hello','goodbye')) | +----------------------------------------------+ | 0 | +----------------------------------------------+ 1 row in set (4.74 sec) Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html5"fYEARSyntax: YEAR(date) Returns the year for date, in the range 1000 to 9999, or 0 for the "zero" date. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 2mysql> SELECT YEAR('1987-01-01'); -> 1987 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html^2g SHOW ENGINESyntax: SHOW ENGINE engine_name {STATUS | MUTEX} SHOW ENGINE displays operational information about a storage engine. The following statements currently are supported: SHOW ENGINE INNODB STATUS SHOW ENGINE INNODB MUTEX SHOW ENGINE {NDB | NDBCLUSTER} STATUS Older (and now deprecated) synonyms are SHOW INNODB STATUS for SHOW ENGINE INNODB STATUS and SHOW MUTEX STATUS for SHOW ENGINE INNODB MUTEX. In MySQL 5.0, SHOW ENGINE INNODB MUTEX is invoked as SHOW MUTEX STATUS. The latter statement displays similar information but in a somewhat different output format. SHOW ENGINE BDB LOGS formerly displayed status information about BDB log files. As of MySQL 5.1.12, the BDB storage engine is not supported, and this statement produces a warning. SHOW ENGINE INNODB STATUS displays extensive information about the state of the InnoDB storage engine. The InnoDB Monitors provide additional information about InnoDB processing. See http://dev.mysql.com/doc/refman/5.1/en/innodb-monitor.html. SHOW ENGINE INNODB MUTEX displays InnoDB mutex statistics. From MySQL 5.1.2 to 5.1.14, the statement displays the following output fields: o Type Always InnoDB. o Name The mutex name and the source file where it is implemented. Example: &pool->mutex:mem0pool.c The mutex name indicates its purpose. For example, the log_sys mutex is used by the InnoDB logging subsystem and indicates how intensive logging activity is. The buf_pool mutex protects the InnoDB buffer pool. o Status The mutex status. The fields contains several values: o count indicates how many times the mutex was requested. o spin_waits indicates how many times the spinlock had to run. o spin_rounds indicates the number of spinlock rounds. (spin_rounds divided by spin_waits provides the average round count.) o os_waits indicates the number of operating system waits. This occurs when the spinlock did not work (the mutex was not locked during the spinlock and it was necessary to yield to the operating system and wait). o os_yields indicates the number of times a the thread trying to lock a mutex gave up its timeslice and yielded to the operating system (on the presumption that allowing other threads to run will free the mutex so that it can be locked). o os_wait_times indicates the amount of time (in ms) spent in operating system waits, if the timed_mutexes system variable is 1 (ON). If timed_mutexes is 0 (OFF), timing is disabled, so os_wait_times is 0. timed_mutexes is off by default. From MySQL 5.1.15 on, the statement displays the following output fields: o Type Always InnoDB. o Name The source file where the mutex is implemented, and the line number in the file where the mutex is created. The line number may change depending on your version of MySQL. o Status This field displays the same values as previously described (count, spin_waits, spin_rounds, os_waits, os_yields, os_wait_times), but only if UNIV_DEBUG was defined at MySQL compilation time (for example, in include/univ.h in the InnoDB part of the MySQL source tree). If UNIV_DEBUG was not defined, the statement displays only the os_waits value. In the latter case (without UNIV_DEBUG), the information on which the output is based is insufficient to distinguish regular mutexes and mutexes that protect rw-locks (which allow multiple readers or a single writer). Consequently, the output may appear to contain multiple rows for the same mutex. Information from this statement can be used to diagnose system problems. For example, large values of spin_waits and spin_rounds may indicate scalability problems. If the server has the NDBCLUSTER storage engine enabled, SHOW ENGINE NDB STATUS displays cluster status information such as the number of connected data nodes, the cluster connectstring, and cluster binlog epochs, as well as counts of various Cluster API objects created by the MySQL Server when connected to the cluster. Sample output from this statement is shown here: mysql> SHOW ENGINE NDB STATUS; +------------+-----------------------+--------------------------------------------------+ | Type | Name | Status | +------------+-----------------------+--------------------------------------------------+ | ndbcluster | connection | cluster_node_id=7, connected_host=192.168.0.103, connected_port=1186, number_of_data_nodes=4, number_of_ready_data_nodes=3, connect_count=0 | | ndbcluster | NdbTransaction | created=6, free=0, sizeof=212 | | ndbcluster | NdbOperation | created=8, free=8, sizeof=660 | | ndbcluster | NdbIndexScanOperation | created=1, free=1, sizeof=744 | | ndbcluster | NdbIndexOperation | created=0, free=0, sizeof=664 | | ndbcluster | NdbRecAttr | created=1285, free=1285, sizeof=60 | | ndbcluster | NdbApiSignal | created=16, free=16, sizeof=136 | | ndbcluster | NdbLabel | created=0, free=0, sizeof=196 | | ndbcluster | NdbBranch | created=0, free=0, sizeof=24 | | ndbcluster | NdbSubroutine | created=0, free=0, sizeof=68 | | ndbcluster | NdbCall | created=0, free=0, sizeof=16 | | ndbcluster | NdbBlob | created=1, free=1, sizeof=264 | | ndbcluster | NdbReceiver | created=4, free=0, sizeof=68 | | ndbcluster | binlog | latest_epoch=155467, latest_trans_epoch=148126, latest_received_binlog_epoch=0, latest_handled_binlog_epoch=0, latest_applied_binlog_epoch=0 | +------------+-----------------------+--------------------------------------------------+ The rows with connection and binlog in the Name column were added to the output of this statement in MySQL 5.1. The Status column in each of these rows provides information about the MySQL server's connection to the cluster and about the cluster binary log's status, respectively. The Status information is in the form of comma-delimited set of name/value pairs. URL: http://dev.mysql.com/doc/refman/5.1/en/show-engine.html 7http://dev.mysql.com/doc/refman/5.1/en/show-engine.html2h NAME_CONSThSyntax: NAME_CONST(name,value) Returns the given value. When used to produce a result set column, NAME_CONST() causes the column to have the given name. The arguments should be constants. mysql> SELECT NAME_CONST('myname', 14); +--------+ | myname | +--------+ | 14 | +--------+ URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.htmlq2i RELEASE_LOCKSyntax: RELEASE_LOCK(str) Releases the lock named by the string str that was obtained with GET_LOCK(). Returns 1 if the lock was released, 0 if the lock was not established by this thread (in which case the lock is not released), and NULL if the named lock did not exist. The lock does not exist if it was never obtained by a call to GET_LOCK() or if it has previously been released. The DO statement is convenient to use with RELEASE_LOCK(). See [HELP DO]. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"jIS NULLxSyntax: IS NULL Tests whether a value is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html Emysql> SELECT 1 IS NULL, 0 IS NULL, NULL IS NULL; -> 0, 0, 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"k CONVERT_TZSyntax: CONVERT_TZ(dt,from_tz,to_tz) CONVERT_TZ() converts a datetime value dt from the time zone given by from_tz to the time zone given by to_tz and returns the resulting value. Time zones are specified as described in http://dev.mysql.com/doc/refman/5.1/en/time-zone-support.html. This function returns NULL if the arguments are invalid. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET'); -> '2004-01-01 13:00:00' mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00'); -> '2004-01-01 22:00:00' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmla"l TIME_TO_SECSyntax: TIME_TO_SEC(time) Returns the time argument, converted to seconds. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html omysql> SELECT TIME_TO_SEC('22:23:00'); -> 80580 mysql> SELECT TIME_TO_SEC('00:39:38'); -> 2378 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlt"mWEEKDAYSyntax: WEEKDAY(date) Returns the weekday index for date (0 = Monday, 1 = Tuesday, ... 6 = Sunday). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mmysql> SELECT WEEKDAY('2008-02-03 22:23:00'); -> 6 mysql> SELECT WEEKDAY('2007-11-06'); -> 1 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"n EXPORT_SET$4Syntax: EXPORT_SET(bits,on,off[,separator[,number_of_bits]]) Returns a string such that for every bit set in the value bits, you get an on string and for every bit not set in the value, you get an off string. Bits in bits are examined from right to left (from low-order to high-order bits). Strings are added to the result from left to right, separated by the separator string (the default being the comma character ","). The number of bits examined is given by number_of_bits (defaults to 64). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT EXPORT_SET(5,'Y','N',',',4); -> 'Y,N,Y,N' mysql> SELECT EXPORT_SET(6,'1','0',',',10); -> '0,1,1,0,0,0,0,0,0,0' SELECT TIME('2003-12-31 01:02:03'); -> '01:02:03' mysql> SELECT TIME('2003-12-31 01:02:03.000123'); -> '01:02:03.000123' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"qDATE_ADDSyntax: DATE_ADD(date,INTERVAL expr unit), DATE_SUB(date,INTERVAL expr unit) These functions perform date arithmetic. The date argument specifies the starting date or datetime value. expr is an expression specifying the interval value to be added or subtracted from the starting date. expr is a string; it may start with a "-" for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Umysql> SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND; -> '2009-01-01 00:00:00' mysql> SELECT INTERVAL 1 DAY + '2008-12-31'; -> '2009-01-01' mysql> SELECT '2005-01-01' - INTERVAL 1 SECOND; -> '2004-12-31 23:59:59' mysql> SELECT DATE_ADD('2000-12-31 23:59:59', -> INTERVAL 1 SECOND); -> '2001-01-01 00:00:00' mysql> SELECT DATE_ADD('2010-12-31 23:59:59', -> INTERVAL 1 DAY); -> '2011-01-01 23:59:59' mysql> SELECT DATE_ADD('2100-12-31 23:59:59', -> INTERVAL '1:1' MINUTE_SECOND); -> '2101-01-01 00:01:00' mysql> SELECT DATE_SUB('2005-01-01 00:00:00', -> INTERVAL '1 1:1:1' DAY_SECOND); -> '2004-12-30 22:58:59' mysql> SELECT DATE_ADD('1900-01-01 00:00:00', -> INTERVAL '-1 10' DAY_HOUR); -> '1899-12-30 14:00:00' mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY); -> '1997-12-02' mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002', -> INTERVAL '1.999999' SECOND_MICROSECOND); -> '1993-01-01 00:00:01.000001' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlG2rCAST$Syntax: CAST(expr AS type) The CAST() function takes a value of one type and produce a value of another type, similar to CONVERT(). See the description of CONVERT() for more information. URL: http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html :http://dev.mysql.com/doc/refman/5.1/en/cast-functions.html2s SOUNDS LIKE$Syntax: expr1 SOUNDS LIKE expr2 This is the same as SOUNDEX(expr1) = SOUNDEX(expr2). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT PERIOD_DIFF(200802,200703); -> 11 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlA"uLIKE$Syntax: expr LIKE pat [ESCAPE 'escape_char'] Pattern matching using SQL simple regular expression comparison. Returns 1 (TRUE) or 0 (FALSE). If either expr or pat is NULL, the result is NULL. The pattern need not be a literal string. For example, it can be specified as a string expression or table column. URL: http://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html emysql> SELECT 'David!' LIKE 'David_'; -> 1 mysql> SELECT 'David!' LIKE '%D%v%'; -> 1 Ghttp://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.htmlq2v MULTIPOINTMultiPoint(pt1,pt2,...) Constructs a WKB MultiPoint value using WKB Point arguments. If any argument is not a WKB Point, the return value is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions `http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-mysql-specific-functions"w>>}Syntax: >> Shifts a longlong (BIGINT) number to the right. URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html #mysql> SELECT 4 >> 2; -> 1 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html(2xFETCHSyntax: FETCH cursor_name INTO var_name [, var_name] ... This statement fetches the next row (if a row exists) using the specified open cursor, and advances the cursor pointer. If no more rows are available, a No Data condition occurs with SQLSTATE value 02000. To detect this condition, you can set up a handler for it (or for a NOT FOUND condition). An example is shown in http://dev.mysql.com/doc/refman/5.1/en/cursors.html. URL: http://dev.mysql.com/doc/refman/5.1/en/fetch.html 1http://dev.mysql.com/doc/refman/5.1/en/fetch.html"yAVGSyntax: AVG([DISTINCT] expr) Returns the average value of expr. The DISTINCT option can be used to return the average of the distinct values of expr. AVG() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html lmysql> SELECT student_name, AVG(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.htmlE2z TRUE FALSEThe constants TRUE and FALSE evaluate to 1 and 0, respectively. The constant names can be written in any lettercase. mysql> SELECT TRUE, true, FALSE, false; -> 1, 1, 0, 0 URL: http://dev.mysql.com/doc/refman/5.1/en/boolean-values.html :http://dev.mysql.com/doc/refman/5.1/en/boolean-values.html"{ MBRWITHINMBRWithin(g1,g2) Returns 1 or 0 to indicate whether the Minimum Bounding Rectangle of g1 is within the Minimum Bounding Rectangle of g2. This tests the opposite relationship as MBRContains(). URL: http://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html mysql> SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); mysql> SET @g2 = GeomFromText('Polygon((0 0,0 5,5 5,5 0,0 0))'); mysql> SELECT MBRWithin(@g1,@g2), MBRWithin(@g2,@g1); +--------------------+--------------------+ | MBRWithin(@g1,@g2) | MBRWithin(@g2,@g1) | +--------------------+--------------------+ | 1 | 0 | +--------------------+--------------------+ Ehttp://dev.mysql.com/doc/refman/5.1/en/relations-on-geometry-mbr.html"|INFSyntax: expr IN (value,...) Returns 1 if expr is equal to any of the values in the IN list, else returns 0. If all values are constants, they are evaluated according to the type of expr and sorted. The search for the item then is done using a binary search. This means IN is very quick if the IN value list consists entirely of constants. Otherwise, type conversion takes place according to the rules described in http://dev.mysql.com/doc/refman/5.1/en/type-conversion.html, but applied to all the arguments. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html hmysql> SELECT 2 IN (0,3,5,7); -> 0 mysql> SELECT 'wefwf' IN ('wee','wefwf','weg'); -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.htmlq"}QUOTE$Syntax: QUOTE(str) Quotes a string to produce a result that can be used as a properly escaped data value in an SQL statement. The string is returned enclosed by single quotes and with each instance of single quote ("'"), backslash ("\"), ASCII NUL, and Control-Z preceded by a backslash. If the argument is NULL, the return value is the word "NULL" without enclosing single quotes. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html `mysql> SELECT QUOTE('Don\'t!'); -> 'Don\'t!' mysql> SELECT QUOTE(NULL); -> NULL help search_string If you provide an argument to the help command, mysql uses it as a search string to access server-side help from the contents of the MySQL Reference Manual. The proper operation of this command requires that the help tables in the mysql database be initialized with help topic information (see http://dev.mysql.com/doc/refman/5.1/en/server-side-help-support.html). If there is no match for the search string, the search fails: mysql> help me Nothing found Please try to run 'help contents' for a list of all accessible topics Use help contents to see a list of the help categories: mysql> help contents You asked for help about help category: "Contents" For more information, type 'help ', where is one of the following categories: Account Management Administration Data Definition Data Manipulation Data Types Functions Functions and Modifiers for Use with GROUP BY Geographic Features Language Structure Plugins Storage Engines Stored Routines Table Maintenance Transactions Triggers If the search string matches multiple items, mysql shows a list of matching topics: mysql> help logs Many help items for your request exist. To make a more specific request, please type 'help ', where is one of the following topics: SHOW SHOW BINARY LOGS SHOW ENGINE SHOW LOGS Use a topic as the search string to see the help entry for that topic: mysql> help show binary logs Name: 'SHOW BINARY LOGS' Description: Syntax: SHOW BINARY LOGS SHOW MASTER LOGS Lists the binary log files on the server. This statement is used as part of the procedure described in [purge-binary-logs], that shows how to determine which logs can be purged. mysql> SHOW BINARY LOGS; +---------------+-----------+ | Log_name | File_size | +---------------+-----------+ | binlog.000015 | 724935 | | binlog.000016 | 733481 | +---------------+-----------+ URL: http://dev.mysql.com/doc/refman/5.1/en/mysql-server-side-help.html Bhttp://dev.mysql.com/doc/refman/5.1/en/mysql-server-side-help.html*"QUARTERSyntax: QUARTER(date) Returns the quarter of the year for date, in the range 1 to 4. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 2mysql> SELECT QUARTER('2008-04-01'); -> 2 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2POSITION$Syntax: POSITION(substr IN str) POSITION(substr IN str) is a synonym for LOCATE(substr,str). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT customer_address FROM customer_table > WHERE crypted_credit_card = DES_ENCRYPT('credit_card_number'); @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html2CEIL~Syntax: CEIL(X) CEIL() is a synonym for CEILING(). URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"LENGTH$;Syntax: LENGTH(str) Returns the length of the string str, measured in bytes. A multi-byte character counts as multiple bytes. This means that for a string containing five two-byte characters, LENGTH() returns 10, whereas CHAR_LENGTH() returns 5. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html +mysql> SELECT LENGTH('text'); -> 4 SET @pt = 'Point(56.7 53.34)'; mysql> SELECT Y(GeomFromText(@pt)); +----------------------+ | Y(GeomFromText(@pt)) | +----------------------+ | 53.34 | +----------------------+ `http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#point-property-functions2SHOW INNODB STATUSSyntax: SHOW INNODB STATUS In MySQL 5.1, this is a deprecated synonym for SHOW ENGINE INNODB STATUS. See [HELP SHOW ENGINE]. URL: http://dev.mysql.com/doc/refman/5.1/en/show-innodb-status.html >http://dev.mysql.com/doc/refman/5.1/en/show-innodb-status.html2CHECKSUM TABLE.Syntax: CHECKSUM TABLE tbl_name [, tbl_name] ... [ QUICK | EXTENDED ] CHECKSUM TABLE reports a table checksum. With QUICK, the live table checksum is reported if it is available, or NULL otherwise. This is very fast. A live checksum is enabled by specifying the CHECKSUM=1 table option when you create the table; currently, this is supported only for MyISAM tables. See [HELP CREATE TABLE]. With EXTENDED, the entire table is read row by row and the checksum is calculated. This can be very slow for large tables. If neither QUICK nor EXTENDED is specified, MySQL returns a live checksum if the table storage engine supports it and scans the table otherwise. For a non-existent table, CHECKSUM TABLE returns NULL and generates a warning. The checksum value depends on the table row format. If the row format changes, the checksum also changes. For example, the storage format for VARCHAR changed between MySQL 4.1 and 5.0, so if a 4.1 table is upgraded to MySQL 5.0, the checksum value may change. URL: http://dev.mysql.com/doc/refman/5.1/en/checksum-table.html :http://dev.mysql.com/doc/refman/5.1/en/checksum-table.html"NUMINTERIORRINGSNumInteriorRings(poly) Returns the number of interior rings in the Polygon value poly. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functions Ymysql> SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT NumInteriorRings(GeomFromText(@poly)); +---------------------------------------+ | NumInteriorRings(GeomFromText(@poly)) | +---------------------------------------+ | 1 | +---------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functions" INTERIORRINGNInteriorRingN(poly,N) Returns the N-th interior ring for the Polygon value poly as a LineString. Rings are numbered beginning with 1. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functions mysql> SET @poly = -> 'Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'; mysql> SELECT AsText(InteriorRingN(GeomFromText(@poly),1)); +----------------------------------------------+ | AsText(InteriorRingN(GeomFromText(@poly),1)) | +----------------------------------------------+ | LINESTRING(1 1,1 2,2 2,2 1,1 1) | +----------------------------------------------+ bhttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#polygon-property-functions"UTC_TIMESyntax: UTC_TIME, UTC_TIME() Returns the current UTC time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Omysql> SELECT UTC_TIME(), UTC_TIME() + 0; -> '18:07:53', 180753.000000 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2 DROP FUNCTION&LThe DROP FUNCTION statement is used to drop stored functions and user-defined functions (UDFs): o For information about dropping stored functions, see [HELP DROP PROCEDURE]. o For information about dropping user-defined functions, see [HELP DROP FUNCTION UDF]. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-function.html 9http://dev.mysql.com/doc/refman/5.1/en/drop-function.html42 ALTER EVENT&Syntax: ALTER [DEFINER = { user | CURRENT_USER }] EVENT event_name [ON SCHEDULE schedule] [ON COMPLETION [NOT] PRESERVE] [RENAME TO new_event_name] [ENABLE | DISABLE | DISABLE ON SLAVE] [COMMENT 'comment'] [DO sql_statement] The ALTER EVENT statement is used to change one or more of the characteristics of an existing event without the need to drop and recreate it. The syntax for each of the DEFINER, ON SCHEDULE, ON COMPLETION, COMMENT, ENABLE / DISABLE, and DO clauses is exactly the same as when used with CREATE EVENT. (See [HELP CREATE EVENT].) Support for the DEFINER clause was added in MySQL 5.1.17. Beginning with MySQL 5.1.12, any user can alter an event defined on a database for which that user has the EVENT privilege. When a user executes a successful ALTER EVENT statement, that user becomes the definer for the affected event. (In MySQL 5.1.11 and earlier, an event could be altered only by its definer, or by a user having the SUPER privilege.) ALTER EVENT works only with an existing event: mysql> ALTER EVENT no_such_event > ON SCHEDULE > EVERY '2:3' DAY_HOUR; ERROR 1517 (HY000): Unknown event 'no_such_event' URL: http://dev.mysql.com/doc/refman/5.1/en/alter-event.html 7http://dev.mysql.com/doc/refman/5.1/en/alter-event.html2STDDEV@Syntax: STDDEV(expr) Returns the population standard deviation of expr. This function is provided for compatibility with Oracle. The standard SQL function STDDEV_POP() can be used instead. This function returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2DATE_SUBSyntax: DATE_SUB(date,INTERVAL expr unit) See the description for DATE_ADD(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" PERIOD_ADDSyntax: PERIOD_ADD(P,N) Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM. Note that the period argument P is not a date value. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 6mysql> SELECT PERIOD_ADD(200801,2); -> 200803 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"|XSyntax: | Bitwise OR: URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html %mysql> SELECT 29 | 15; -> 31 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.htmlP2 GEOMFROMTEXTGeomFromText(wkt[,srid]), GeometryFromText(wkt[,srid]) Constructs a geometry value of any type using its WKT representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkt-functions" UUID_SHORT"Syntax: UUID_SHORT() Returns a "short" universal identifier as a 64-bit unsigned integer (rather than a string-form 128-bit identifier as returned by the UUID() function). The value of UUID_SHORT() is guaranteed to be unique if the following conditions hold: o The server_id of the current host is unique among your set of master and slave servers o server_id is between 0 and 255 o You don't set back your system time for your server between mysqld restarts o You do not invoke UUID_SHORT() on average more than 16 million times per second between mysqld restarts The UUID_SHORT() return value is constructed this way: (server_id & 255) << 56 + (server_startup_time_in_seconds << 24) + incremented_variable++; URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html :mysql> SELECT UUID_SHORT(); -> 92395783831158784 Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html<"RIGHT$Syntax: RIGHT(str,len) Returns the rightmost len characters from the string str, or NULL if any argument is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html 7mysql> SELECT RIGHT('foobarbar', 4); -> 'rbar' SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30'); -> 1 mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31'); -> -31 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2DROP TABLESPACE&NSyntax: DROP TABLESPACE tablespace_name ENGINE [=] engine_name This statement drops a tablespace that was previously created using CREATE TABLESPACE (see [HELP CREATE TABLESPACE]). *Important*: The tablespace to be dropped must not contain any data files; in other words, before you can drop a tablespace, you must first drop each of its data files using ALTER TABLESPACE ... DROP DATAFILE (see [HELP ALTER TABLESPACE]). The ENGINE clause (required) specifies the storage engine used by the tablespace. In MySQL 5.1, the only accepted values for engine_name are NDB and NDBCLUSTER. DROP TABLESPACE was added in MySQL 5.1.6. In MySQL 5.1, it is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-disk-data.html. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-tablespace.html ;http://dev.mysql.com/doc/refman/5.1/en/drop-tablespace.html2DROP PROCEDURE&,Syntax: DROP {PROCEDURE | FUNCTION} [IF EXISTS] sp_name This statement is used to drop a stored procedure or function. That is, the specified routine is removed from the server. You must have the ALTER ROUTINE privilege for the routine. (That privilege is granted automatically to the routine creator.) The IF EXISTS clause is a MySQL extension. It prevents an error from occurring if the procedure or function does not exist. A warning is produced that can be viewed with SHOW WARNINGS. URL: http://dev.mysql.com/doc/refman/5.1/en/drop-procedure.html :http://dev.mysql.com/doc/refman/5.1/en/drop-procedure.html2 CHECK TABLESyntax: CHECK TABLE tbl_name [, tbl_name] ... [option] ... option = {FOR UPGRADE | QUICK | FAST | MEDIUM | EXTENDED | CHANGED} CHECK TABLE checks a table or tables for errors. CHECK TABLE works for MyISAM, InnoDB, and ARCHIVE tables. Starting with MySQL 5.1.9, CHECK TABLE is also valid for CSV tables, see http://dev.mysql.com/doc/refman/5.1/en/csv-storage-engine.html. For MyISAM tables, the key statistics are updated as well. CHECK TABLE can also check views for problems, such as tables that are referenced in the view definition that no longer exist. CHECK TABLE is not supported for partitioned tables before MySQL 5.1.27. URL: http://dev.mysql.com/doc/refman/5.1/en/check-table.html 7http://dev.mysql.com/doc/refman/5.1/en/check-table.htmli"BIN$Syntax: BIN(N) Returns a string representation of the binary value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,2). Returns NULL if N is NULL. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html )mysql> SELECT BIN(12); -> '1100' SELECT SHA1('abc'); -> 'a9993e364706816aba3e25717850c26c9cd0d89d' @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html2SUBSTR$Syntax: SUBSTR(str,pos), SUBSTR(str FROM pos), SUBSTR(str,pos,len), SUBSTR(str FROM pos FOR len) SUBSTR() is a synonym for SUBSTRING(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT PASSWORD('badpwd'); -> '*AAB3E285149C0135D51A520E1940DD3263DC008C' @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html.2CHAR[NATIONAL] CHAR[(M)] [CHARACTER SET charset_name] [COLLATE collation_name] A fixed-length string that is always right-padded with spaces to the specified length when stored. M represents the column length in characters. The range of M is 0 to 255. If M is omitted, the length is 1. *Note*: Trailing spaces are removed when CHAR values are retrieved unless the PAD_CHAR_TO_FULL_LENGTH SQL mode is enabled. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html"UTC_DATESyntax: UTC_DATE, UTC_DATE() Returns the current UTC date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Lmysql> SELECT UTC_DATE(), UTC_DATE() + 0; -> '2003-08-14', 20030814 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" DIMENSION#CDimension(g) Returns the inherent dimension of the geometry value g. The result can be -1, 0, 1, or 2. The meaning of these values is given in http://dev.mysql.com/doc/refman/5.1/en/gis-class-geometry.html. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions =mysql> SELECT Dimension(GeomFromText('LineString(1 1,2 2)')); +------------------------------------------------+ | Dimension(GeomFromText('LineString(1 1,2 2)')) | +------------------------------------------------+ | 1 | +------------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functionsr"COUNT DISTINCTSyntax: COUNT(DISTINCT expr,[expr...]) Returns a count of the number of different non-NULL values. COUNT(DISTINCT) returns 0 if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html 4mysql> SELECT COUNT(DISTINCT results) FROM student; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html2BITBIT[(M)] A bit-field type. M indicates the number of bits per value, from 1 to 64. The default is 1 if M is omitted. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html82EQUALSEquals(g1,g2) Returns 1 or 0 to indicate whether g1 is spatially equal to g2. URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html 2SHOW CREATE VIEWSyntax: SHOW CREATE VIEW view_name This statement shows a CREATE VIEW statement that creates the given view. URL: http://dev.mysql.com/doc/refman/5.1/en/show-create-view.html SELECT INTERVAL(23, 1, 15, 17, 30, 44, 200); -> 3 mysql> SELECT INTERVAL(10, 1, 10, 100, 1000); -> 2 mysql> SELECT INTERVAL(22, 23, 30, 44, 200); -> 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html" FROM_DAYSSyntax: FROM_DAYS(N) Given a day number N, returns a DATE value. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 9mysql> SELECT FROM_DAYS(730669); -> '2007-07-03' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2ALTER PROCEDURE&+Syntax: ALTER {PROCEDURE | FUNCTION} sp_name [characteristic ...] characteristic: { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } | COMMENT 'string' This statement can be used to change the characteristics of a stored routine (that is, a stored procedure or stored function). More than one change may be specified in an ALTER PROCEDURE or ALTER FUNCTION statement. However, you cannot change the parameters or routine body of a stored routine using this statement; to make such changes, you must first drop the routine using DROP PROCEDURE or DROP FUNCTION, then re-create the routine using CREATE PROCEDURE or CREATE FUNCTION. You must have the ALTER ROUTINE privilege for the routine. (That privilege is granted automatically to the routine creator.) If binary logging is enabled, the ALTER FUNCTION statement might also require the SUPER privilege, as described in http://dev.mysql.com/doc/refman/5.1/en/stored-programs-logging.html. URL: http://dev.mysql.com/doc/refman/5.1/en/alter-procedure.html ;http://dev.mysql.com/doc/refman/5.1/en/alter-procedure.html$" BIT_COUNTSyntax: BIT_COUNT(N) Returns the number of bits that are set in the argument N. URL: http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html Cmysql> SELECT BIT_COUNT(29), BIT_COUNT(b'101010'); -> 4, 3 9http://dev.mysql.com/doc/refman/5.1/en/bit-functions.html2 OCTET_LENGTH$Syntax: OCTET_LENGTH(str) OCTET_LENGTH() is a synonym for LENGTH(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0; -> '2003-08-14 18:08:04', 20030814180804.000000 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlN" AES_ENCRYPT Syntax: AES_ENCRYPT(str,key_str) AES_ENCRYPT() and AES_DECRYPT() allow encryption and decryption of data using the official AES (Advanced Encryption Standard) algorithm, previously known as "Rijndael." Encoding with a 128-bit key length is used, but you can extend it up to 256 bits by modifying the source. We chose 128 bits because it is much faster and it is secure enough for most purposes. AES_ENCRYPT() encrypts a string and returns a binary string. AES_DECRYPT() decrypts the encrypted string and returns the original string. The input arguments may be any length. If either argument is NULL, the result of this function is also NULL. Because AES is a block-level algorithm, padding is used to encode uneven length strings and so the result string length may be calculated using this formula: 16 x (trunc(string_length / 16) + 1) If AES_DECRYPT() detects invalid data or incorrect padding, it returns NULL. However, it is possible for AES_DECRYPT() to return a non-NULL value (possibly garbage) if the input data or the key is invalid. You can use the AES functions to store data in an encrypted form by modifying your queries: URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html 9INSERT INTO t VALUES (1,AES_ENCRYPT('text','password')); @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html"+]Syntax: + Addition: URL: http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.html mysql> SELECT 3+5; -> 8 @http://dev.mysql.com/doc/refman/5.1/en/arithmetic-functions.htmlp" INET_NTOASyntax: INET_NTOA(expr) Given a numeric network address (4 or 8 byte), returns the dotted-quad representation of the address as a string. URL: http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html Amysql> SELECT INET_NTOA(3520061480); -> '209.207.224.40' Chttp://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html"ACOSSyntax: ACOS(X) Returns the arc cosine of X, that is, the value whose cosine is X. Returns NULL if X is not in the range -1 to 1. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html mysql> SELECT ACOS(1); -> 0 mysql> SELECT ACOS(1.0001); -> NULL mysql> SELECT ACOS(0); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2 ISOLATIONSyntax: SET [GLOBAL | SESSION] TRANSACTION ISOLATION LEVEL { READ UNCOMMITTED | READ COMMITTED | REPEATABLE READ | SERIALIZABLE } This statement sets the transaction isolation level for the next transaction, globally, or for the current session: o The default behavior (without any SESSION or GLOBAL keyword) is to set the isolation level for the next (not started) transaction. o With the GLOBAL keyword, the statement sets the default transaction level globally for all subsequent sessions created from that point on (but not for existing connections). You need the SUPER privilege to do this. o With the SESSION keyword, the statement sets the default transaction level for all subsequent transactions performed within the current session. To set the initial default global isolation level for mysqld, use the --transaction-isolation option. See http://dev.mysql.com/doc/refman/5.1/en/server-options.html. For information about InnoDB and transaction isolation level, see http://dev.mysql.com/doc/refman/5.1/en/innodb-transaction-isolation.htm l. InnoDB supports each of the levels described here. The default level is REPEATABLE READ. See also http://dev.mysql.com/doc/refman/5.1/en/innodb-locks-set.html, for additional information about how InnoDB uses locks to execute various types of statements. In MySQL 5.1, if the READ COMMITTED isolation level is used or the innodb_locks_unsafe_for_binlog system variable is enabled, there is no InnoDB gap locking except in constraint checking. Also, record locks for non-matching rows are released after MySQL has evaluated the WHERE condition. A detailed list of the transaction levels supported by MySQL and the various storage engines follows: o READ UNCOMMITTED SELECT statements are performed in a non-locking fashion, but a possible earlier version of a row might be used. Thus, using this isolation level, such reads are not consistent. This is also called a "dirty read." Otherwise, this isolation level works like READ COMMITTED. o READ COMMITTED A somewhat Oracle-like isolation level. All SELECT ... FOR UPDATE and SELECT ... LOCK IN SHARE MODE statements lock only the index records, not the gaps before them, and thus allow the free insertion of new records next to locked records. UPDATE and DELETE statements using a unique index with a unique search condition lock only the index record found, not the gap before it. In range-type UPDATE and DELETE statements, InnoDB must set next-key or gap locks and block insertions by other users to the gaps covered by the range. This is necessary because "phantom rows" must be blocked for MySQL replication and recovery to work. Consistent reads behave as in Oracle: Each consistent read, even within the same transaction, sets and reads its own fresh snapshot. See http://dev.mysql.com/doc/refman/5.1/en/innodb-consistent-read.html. *Note*: As of MySQL 5.1, if you use READ COMMITTED (which is equivalent to enabling innodb_locks_unsafe_for_binlog in 5.0), you must use row-based binary logging. o REPEATABLE READ This is the default isolation level of InnoDB. SELECT ... FOR UPDATE, SELECT ... LOCK IN SHARE MODE, UPDATE, and DELETE statements that use a unique index with a unique search condition lock only the index record found, not the gap before it. With other search conditions, these operations employ next-key locking, so they lock the index range scanned with next-key or gap locks, and block insertions by other users to the gaps covered by the range. In consistent reads, there is an important difference from the READ COMMITTED isolation level: All consistent reads within the same transaction read the same snapshot established by the first read. This convention means that if you issue several plain SELECT statements within the same transaction, these SELECT statements are consistent also with respect to each other. See http://dev.mysql.com/doc/refman/5.1/en/innodb-consistent-read.html. o SERIALIZABLE This level is like REPEATABLE READ, but InnoDB implicitly converts all plain SELECT statements to SELECT ... LOCK IN SHARE MODE. URL: http://dev.mysql.com/doc/refman/5.1/en/set-transaction.html ;http://dev.mysql.com/doc/refman/5.1/en/set-transaction.html>"CEILINGSyntax: CEILING(X) Returns the smallest integer value not less than X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Vmysql> SELECT CEILING(1.23); -> 2 mysql> SELECT CEILING(-1.23); -> -1 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlE"SINSyntax: SIN(X) Returns the sine of X, where X is given in radians. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html emysql> SELECT SIN(PI()); -> 1.2246063538224e-16 mysql> SELECT ROUND(SIN(PI())); -> 0 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlu" DAYOFWEEKSyntax: DAYOFWEEK(date) Returns the weekday index for date (1 = Sunday, 2 = Monday, ..., 7 = Saturday). These index values correspond to the ODBC standard. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html 4mysql> SELECT DAYOFWEEK('2007-02-03'); -> 7 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2SHOW PROCESSLIST5Syntax: SHOW [FULL] PROCESSLIST SHOW PROCESSLIST shows you which threads are running. You can also get this information from the INFORMATION_SCHEMA PROCESSLIST table or the mysqladmin processlist command. If you have the PROCESS privilege, you can see all threads. Otherwise, you can see only your own threads (that is, threads associated with the MySQL account that you are using). If you do not use the FULL keyword, only the first 100 characters of each statement are shown in the Info field. URL: http://dev.mysql.com/doc/refman/5.1/en/show-processlist.html SELECT GeometryType(GeomFromText('POINT(1 1)')); +------------------------------------------+ | GeometryType(GeomFromText('POINT(1 1)')) | +------------------------------------------+ | POINT | +------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions3!2 CREATE VIEW&2Syntax: CREATE [OR REPLACE] [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}] [DEFINER = { user | CURRENT_USER }] [SQL SECURITY { DEFINER | INVOKER }] VIEW view_name [(column_list)] AS select_statement [WITH [CASCADED | LOCAL] CHECK OPTION] The CREATE VIEW statement creates a new view, or replaces an existing one if the OR REPLACE clause is given. If the view does not exist, CREATE OR REPLACE VIEW is the same as CREATE VIEW. If the view does exist, CREATE OR REPLACE VIEW is the same as ALTER VIEW. The select_statement is a SELECT statement that provides the definition of the view. (When you select from the view, you select in effect using the SELECT statement.) select_statement can select from base tables or other views. The view definition is "frozen" at creation time, so changes to the underlying tables afterward do not affect the view definition. For example, if a view is defined as SELECT * on a table, new columns added to the table later do not become part of the view. The ALGORITHM clause affects how MySQL processes the view. The DEFINER and SQL SECURITY clauses specify the security context to be used when checking access privileges at view invocation time. The WITH CHECK OPTION clause can be given to constrain inserts or updates to rows in tables referenced by the view. These clauses are described later in this section. The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have the DROP privilege for the view. A view belongs to a database. By default, a new view is created in the default database. To create the view explicitly in a given database, specify the name as db_name.view_name when you create it. mysql> CREATE VIEW test.v AS SELECT * FROM t; Base tables and views share the same namespace within a database, so a database cannot contain a base table and a view that have the same name. Views must have unique column names with no duplicates, just like base tables. By default, the names of the columns retrieved by the SELECT statement are used for the view column names. To define explicit names for the view columns, the optional column_list clause can be given as a list of comma-separated identifiers. The number of names in column_list must be the same as the number of columns retrieved by the SELECT statement. *Note*: Prior to MySQL 5.1.29, When you modify an existing view, the current view definition is backed up and saved. It is stored in that table's database directory, in a subdirectory named arc. The backup file for a view v is named v.frm-00001. If you alter the view again, the next backup is named v.frm-00002. The three latest view backup definitions are stored. Backed up view definitions are not preserved by mysqldump, or any other such programs, but you can retain them using a file copy operation. However, they are not needed for anything but to provide you with a backup of your previous view definition. It is safe to remove these backup definitions, but only while mysqld is not running. If you delete the arc subdirectory or its files while mysqld is running, you will receive an error the next time you try to alter the view: mysql> ALTER VIEW v AS SELECT * FROM t; ERROR 6 (HY000): Error on delete of '.\test\arc/v.frm-0004' (Errcode: 2) Columns retrieved by the SELECT statement can be simple references to table columns. They can also be expressions that use functions, constant values, operators, and so forth. Unqualified table or view names in the SELECT statement are interpreted with respect to the default database. A view can refer to tables or views in other databases by qualifying the table or view name with the proper database name. A view can be created from many kinds of SELECT statements. It can refer to base tables or other views. It can use joins, UNION, and subqueries. The SELECT need not even refer to any tables. The following example defines a view that selects two columns from another table, as well as an expression calculated from those columns: mysql> CREATE TABLE t (qty INT, price INT); mysql> INSERT INTO t VALUES(3, 50); mysql> CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t; mysql> SELECT * FROM v; +------+-------+-------+ | qty | price | value | +------+-------+-------+ | 3 | 50 | 150 | +------+-------+-------+ A view definition is subject to the following restrictions: o The SELECT statement cannot contain a subquery in the FROM clause. o The SELECT statement cannot refer to system or user variables. o Within a stored program, the definition cannot refer to program parameters or local variables. o The SELECT statement cannot refer to prepared statement parameters. o Any table or view referred to in the definition must exist. However, after a view has been created, it is possible to drop a table or view that the definition refers to. In this case, use of the view results in an error. To check a view definition for problems of this kind, use the CHECK TABLE statement. o The definition cannot refer to a TEMPORARY table, and you cannot create a TEMPORARY view. o Any tables named in the view definition must exist at definition time. o You cannot associate a trigger with a view. ORDER BY is allowed in a view definition, but it is ignored if you select from a view using a statement that has its own ORDER BY. For other options or clauses in the definition, they are added to the options or clauses of the statement that references the view, but the effect is undefined. For example, if a view definition includes a LIMIT clause, and you select from the view using a statement that has its own LIMIT clause, it is undefined which limit applies. This same principle applies to options such as ALL, DISTINCT, or SQL_SMALL_RESULT that follow the SELECT keyword, and to clauses such as INTO, FOR UPDATE, LOCK IN SHARE MODE, and PROCEDURE. If you create a view and then change the query processing environment by changing system variables, that may affect the results that you get from the view: mysql> CREATE VIEW v (mycol) AS SELECT 'abc'; Query OK, 0 rows affected (0.01 sec) mysql> SET sql_mode = ''; Query OK, 0 rows affected (0.00 sec) mysql> SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | mycol | +-------+ 1 row in set (0.01 sec) mysql> SET sql_mode = 'ANSI_QUOTES'; Query OK, 0 rows affected (0.00 sec) mysql> SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | abc | +-------+ 1 row in set (0.00 sec) The DEFINER and SQL SECURITY clauses determine which MySQL account to use when checking access privileges for the view when a statement is executed that references the view. They were addded in MySQL 5.1.2. The legal SQL SECURITY characteristic values are DEFINER and INVOKER. These indicate that the required privileges must be held by the user who defined or invoked the view, respectively. The default SQL SECURITY value is DEFINER. If a user value is given for the DEFINER clause, it should be a MySQL account in 'user_name'@'host_name' format (the same format used in the GRANT statement). The user_name and host_name values both are required. The definer can also be given as CURRENT_USER or CURRENT_USER(). The default DEFINER value is the user who executes the CREATE VIEW statement. This is the same as specifying DEFINER = CURRENT_USER explicitly. If you specify the DEFINER clause, these rules determine the legal DEFINER user values: o If you do not have the SUPER privilege, the only legal user value is your own account, either specified literally or by using CURRENT_USER. You cannot set the definer to some other account. o If you have the SUPER privilege, you can specify any syntactically legal account name. If the account does not actually exist, a warning is generated. o If the SQL SECURITY value is DEFINER but the definer account does not exist when the view is referenced, an error occurs. Within a view definition, CURRENT_USER returns the view's DEFINER value by default as of MySQL 5.1.12. For older versions, and for views defined with the SQL SECURITY INVOKER characteristic, CURRENT_USER returns the account for the view's invoker. For information about user auditing within views, see http://dev.mysql.com/doc/refman/5.1/en/account-activity-auditing.html. Within a stored routine that is defined with the SQL SECURITY DEFINER characteristic, CURRENT_USER returns the routine's DEFINER value. This also affects a view defined within such a program, if the view definition contains a DEFINER value of CURRENT_USER. As of MySQL 5.1.2 (when the DEFINER and SQL SECURITY clauses were implemented), view privileges are checked like this: o At view definition time, the view creator must have the privileges needed to use the top-level objects accessed by the view. For example, if the view definition refers to table columns, the creator must have privileges for the columns, as described previously. If the definition refers to a stored function, only the privileges needed to invoke the function can be checked. The privileges required when the function runs can be checked only as it executes: For different invocations of the function, different execution paths within the function might be taken. o When a view is referenced, privileges for objects accessed by the view are checked against the privileges held by the view creator or invoker, depending on whether the SQL SECURITY characteristic is DEFINER or INVOKER, respectively. o If reference to a view causes execution of a stored function, privilege checking for statements executed within the function depend on whether the function is defined with a SQL SECURITY characteristic of DEFINER or INVOKER. If the security characteristic is DEFINER, the function runs with the privileges of its creator. If the characteristic is INVOKER, the function runs with the privileges determined by the view's SQL SECURITY characteristic. Prior to MySQL 5.1.2 (before the DEFINER and SQL SECURITY clauses were implemented), privileges required for objects used in a view are checked at view creation time. Example: A view might depend on a stored function, and that function might invoke other stored routines. For example, the following view invokes a stored function f(): CREATE VIEW v AS SELECT * FROM t WHERE t.id = f(t.name); Suppose that f() contains a statement such as this: IF name IS NULL then CALL p1(); ELSE CALL p2(); END IF; The privileges required for executing statements within f() need to be checked when f() executes. This might mean that privileges are needed for p1() or p2(), depending on the execution path within f(). Those privileges must be checked at runtime, and the user who must possess the privileges is determined by the SQL SECURITY values of the view v and the function f(). The DEFINER and SQL SECURITY clauses for views are extensions to standard SQL. In standard SQL, views are handled using the rules for SQL SECURITY INVOKER. If you invoke a view that was created before MySQL 5.1.2, it is treated as though it was created with a SQL SECURITY DEFINER clause and with a DEFINER value that is the same as your account. However, because the actual definer is unknown, MySQL issues a warning. To make the warning go away, it is sufficient to re-create the view so that the view definition includes a DEFINER clause. The optional ALGORITHM clause is a MySQL extension to standard SQL. It affects how MySQL processes the view. ALGORITHM takes three values: MERGE, TEMPTABLE, or UNDEFINED. The default algorithm is UNDEFINED if no ALGORITHM clause is present. For more information, see http://dev.mysql.com/doc/refman/5.1/en/view-algorithms.html. Some views are updatable. That is, you can use them in statements such as UPDATE, DELETE, or INSERT to update the contents of the underlying table. For a view to be updatable, there must be a one-to-one relationship between the rows in the view and the rows in the underlying table. There are also certain other constructs that make a view non-updatable. The WITH CHECK OPTION clause can be given for an updatable view to prevent inserts or updates to rows except those for which the WHERE clause in the select_statement is true. In a WITH CHECK OPTION clause for an updatable view, the LOCAL and CASCADED keywords determine the scope of check testing when the view is defined in terms of another view. The LOCAL keyword restricts the CHECK OPTION only to the view being defined. CASCADED causes the checks for underlying views to be evaluated as well. When neither keyword is given, the default is CASCADED. For more information about updatable views and the WITH CHECK OPTION clause, see http://dev.mysql.com/doc/refman/5.1/en/view-updatability.html. URL: http://dev.mysql.com/doc/refman/5.1/en/create-view.html 7http://dev.mysql.com/doc/refman/5.1/en/create-view.html"TRIM$oSyntax: TRIM([{BOTH | LEADING | TRAILING} [remstr] FROM] str), TRIM([remstr FROM] str) Returns the string str with all remstr prefixes or suffixes removed. If none of the specifiers BOTH, LEADING, or TRAILING is given, BOTH is assumed. remstr is optional and, if not specified, spaces are removed. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT TRIM(' bar '); -> 'bar' mysql> SELECT TRIM(LEADING 'x' FROM 'xxxbarxxx'); -> 'barxxx' mysql> SELECT TRIM(BOTH 'x' FROM 'xxxbarxxx'); -> 'bar' mysql> SELECT TRIM(TRAILING 'xyz' FROM 'barxxyz'); -> 'barx' SELECT 1 IS TRUE, 0 IS FALSE, NULL IS UNKNOWN; -> 1, 1, 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html" GET_FORMATSyntax: GET_FORMAT({DATE|TIME|DATETIME}, {'EUR'|'USA'|'JIS'|'ISO'|'INTERNAL'}) Returns a format string. This function is useful in combination with the DATE_FORMAT() and the STR_TO_DATE() functions. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT DATE_FORMAT('2003-10-03',GET_FORMAT(DATE,'EUR')); -> '03.10.2003' mysql> SELECT STR_TO_DATE('10.31.2003',GET_FORMAT(DATE,'USA')); -> '2003-10-31' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlN2TINYBLOBTINYBLOB A BLOB column with a maximum length of 255 (28 - 1) bytes. Each TINYBLOB value is stored using a one-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.htmln2 SAVEPOINT%Syntax: SAVEPOINT identifier ROLLBACK [WORK] TO [SAVEPOINT] identifier RELEASE SAVEPOINT identifier InnoDB supports the SQL statements SAVEPOINT, ROLLBACK TO SAVEPOINT, RELEASE SAVEPOINT and the optional WORK keyword for ROLLBACK. URL: http://dev.mysql.com/doc/refman/5.1/en/savepoint.html 5http://dev.mysql.com/doc/refman/5.1/en/savepoint.html6"USERSyntax: USER() Returns the current MySQL username and hostname as a string in the utf8 character set. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html 4mysql> SELECT USER(); -> 'davida@localhost' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html 2 ALTER TABLE& Syntax: ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name alter_specification [, alter_specification] ... alter_specification: table_option ... | ADD [COLUMN] col_name column_definition [FIRST | AFTER col_name ] | ADD [COLUMN] (col_name column_definition,...) | ADD {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD FULLTEXT [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD SPATIAL [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT} | CHANGE [COLUMN] old_col_name new_col_name column_definition [FIRST|AFTER col_name] | MODIFY [COLUMN] col_name column_definition [FIRST | AFTER col_name] | DROP [COLUMN] col_name | DROP PRIMARY KEY | DROP {INDEX|KEY} index_name | DROP FOREIGN KEY fk_symbol | DISABLE KEYS | ENABLE KEYS | RENAME [TO] new_tbl_name | ORDER BY col_name [, col_name] ... | CONVERT TO CHARACTER SET charset_name [COLLATE collation_name] | [DEFAULT] CHARACTER SET [=] charset_name [COLLATE [=] collation_name] | DISCARD TABLESPACE | IMPORT TABLESPACE | partition_options | ADD PARTITION (partition_definition) | DROP PARTITION partition_names | COALESCE PARTITION number | REORGANIZE PARTITION partition_names INTO (partition_definitions) | ANALYZE PARTITION partition_names | CHECK PARTITION partition_names | OPTIMIZE PARTITION partition_names | REBUILD PARTITION partition_names | REPAIR PARTITION partition_names | REMOVE PARTITIONING index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' ALTER TABLE enables you to change the structure of an existing table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself. You can also change the comment for the table and type of the table. URL: http://dev.mysql.com/doc/refman/5.1/en/alter-table.html 7http://dev.mysql.com/doc/refman/5.1/en/alter-table.htmlI2 MPOINTFROMWKB MPointFromWKB(wkb[,srid]), MultiPointFromWKB(wkb[,srid]) Constructs a MULTIPOINT value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions2 CHAR BYTEThe CHAR BYTE data type is an alias for the BINARY data type. This is a compatibility feature. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html2 REPAIR TABLEUSyntax: REPAIR [LOCAL | NO_WRITE_TO_BINLOG] TABLE tbl_name [, tbl_name] ... [QUICK] [EXTENDED] [USE_FRM] REPAIR TABLE repairs a possibly corrupted table. By default, it has the same effect as myisamchk --recover tbl_name. REPAIR TABLE works for MyISAM and for ARCHIVE tables. Starting with MySQL 5.1.9, REPAIR is also valid for CSV tables. See http://dev.mysql.com/doc/refman/5.1/en/myisam-storage-engine.html, and http://dev.mysql.com/doc/refman/5.1/en/archive-storage-engine.html, and http://dev.mysql.com/doc/refman/5.1/en/csv-storage-engine.html This statement requires SELECT and INSERT privileges for the table. REPAIR TABLE is not supported for partitioned tables. See http://dev.mysql.com/doc/refman/5.1/en/partitioning-maintenance.html, for information about alternatives. URL: http://dev.mysql.com/doc/refman/5.1/en/repair-table.html 8http://dev.mysql.com/doc/refman/5.1/en/repair-table.html"MERGE&The MERGE storage engine, also known as the MRG_MyISAM engine, is a collection of identical MyISAM tables that can be used as one. "Identical" means that all tables have identical column and index information. You cannot merge MyISAM tables in which the columns are listed in a different order, do not have exactly the same columns, or have the indexes in different order. However, any or all of the MyISAM tables can be compressed with myisampack. See http://dev.mysql.com/doc/refman/5.1/en/myisampack.html. Differences in table options such as AVG_ROW_LENGTH, MAX_ROWS, or PACK_KEYS do not matter. URL: http://dev.mysql.com/doc/refman/5.1/en/merge-storage-engine.html mysql> CREATE TABLE t1 ( -> a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, -> message CHAR(20)) ENGINE=MyISAM; mysql> CREATE TABLE t2 ( -> a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, -> message CHAR(20)) ENGINE=MyISAM; mysql> INSERT INTO t1 (message) VALUES ('Testing'),('table'),('t1'); mysql> INSERT INTO t2 (message) VALUES ('Testing'),('table'),('t2'); mysql> CREATE TABLE total ( -> a INT NOT NULL AUTO_INCREMENT, -> message CHAR(20), INDEX(a)) -> ENGINE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST; @http://dev.mysql.com/doc/refman/5.1/en/merge-storage-engine.html"2 CREATE TABLE&Syntax: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name (create_definition,...) [table_option] ... [partition_options] Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_option] ... [partition_options] select_statement Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: col_name column_definition | [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | {FULLTEXT|SPATIAL} [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | CHECK (expr) column_definition: data_type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY] [COMMENT 'string'] [reference_definition] [COLUMN_FORMAT {FIXED|DYNAMIC|DEFAULT}] [STORAGE {DISK|MEMORY|DEFAULT}] data_type: BIT[(length)] | TINYINT[(length)] [UNSIGNED] [ZEROFILL] | SMALLINT[(length)] [UNSIGNED] [ZEROFILL] | MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL] | INT[(length)] [UNSIGNED] [ZEROFILL] | INTEGER[(length)] [UNSIGNED] [ZEROFILL] | BIGINT[(length)] [UNSIGNED] [ZEROFILL] | REAL[(length,decimals)] [UNSIGNED] [ZEROFILL] | DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL] | FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL] | DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL] | NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL] | DATE | TIME | TIMESTAMP | DATETIME | YEAR | CHAR[(length)] [CHARACTER SET charset_name] [COLLATE collation_name] | VARCHAR(length) [CHARACTER SET charset_name] [COLLATE collation_name] | BINARY[(length)] | VARBINARY(length) | TINYBLOB | BLOB | MEDIUMBLOB | LONGBLOB | TINYTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | TEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | MEDIUMTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | LONGTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | ENUM(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | SET(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | spatial_type index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name reference_definition: REFERENCES tbl_name (index_col_name,...) [MATCH FULL | MATCH PARTIAL | MATCH SIMPLE] [ON DELETE reference_option] [ON UPDATE reference_option] reference_option: RESTRICT | CASCADE | SET NULL | NO ACTION table_option: ENGINE [=] engine_name | AUTO_INCREMENT [=] value | AVG_ROW_LENGTH [=] value | [DEFAULT] CHARACTER SET [=] charset_name | CHECKSUM [=] {0 | 1} | [DEFAULT] COLLATE [=] collation_name | COMMENT [=] 'string' | CONNECTION [=] 'connect_string' | DATA DIRECTORY [=] 'absolute path to directory' | DELAY_KEY_WRITE [=] {0 | 1} | INDEX DIRECTORY [=] 'absolute path to directory' | INSERT_METHOD [=] { NO | FIRST | LAST } | KEY_BLOCK_SIZE [=] value | MAX_ROWS [=] value | MIN_ROWS [=] value | PACK_KEYS [=] {0 | 1 | DEFAULT} | PASSWORD [=] 'string' | ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT} | TABLESPACE tablespace_name [STORAGE {DISK|MEMORY|DEFAULT}] | UNION [=] (tbl_name[,tbl_name]...) partition_options: PARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) | RANGE(expr) | LIST(expr) } [PARTITIONS num] [SUBPARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) } [SUBPARTITIONS num] ] [(partition_definition [, partition_definition] ...)] partition_definition: PARTITION partition_name [VALUES {LESS THAN {(expr) | MAXVALUE} | IN (value_list)}] [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] [(subpartition_definition [, subpartition_definition] ...)] subpartition_definition: SUBPARTITION logical_name [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] select_statement: [IGNORE | REPLACE] [AS] SELECT ... (Some legal select statement) CREATE TABLE creates a table with the given name. You must have the CREATE privilege for the table. Rules for allowable table names are given in http://dev.mysql.com/doc/refman/5.1/en/identifiers.html. By default, the table is created in the default database. An error occurs if the table exists, if there is no default database, or if the database does not exist. URL: http://dev.mysql.com/doc/refman/5.1/en/create-table.html 8http://dev.mysql.com/doc/refman/5.1/en/create-table.html">aSyntax: > Greater than: URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html "mysql> SELECT 2 > 2; -> 0 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html,2 ANALYZE TABLESyntax: ANALYZE [LOCAL | NO_WRITE_TO_BINLOG] TABLE tbl_name [, tbl_name] ... ANALYZE TABLE analyzes and stores the key distribution for a table. During the analysis, the table is locked with a read lock for MyISAM. For InnoDB the table is locked with a write lock. This statement works with MyISAM, and InnoDB tables. For MyISAM tables, this statement is equivalent to using myisamchk --analyze. For more information on how the analysis works within InnoDB, see http://dev.mysql.com/doc/refman/5.1/en/innodb-restrictions.html. MySQL uses the stored key distribution to decide the order in which tables should be joined when you perform a join on something other than a constant. In addition, key distributions can be used when deciding which indexes to use for a specific table within a query. This statement requires SELECT and INSERT privileges for the table. ANALYZE TABLE is not supported for partitioned tables. URL: http://dev.mysql.com/doc/refman/5.1/en/analyze-table.html 9http://dev.mysql.com/doc/refman/5.1/en/analyze-table.html" MICROSECONDSyntax: MICROSECOND(expr) Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html mysql> SELECT MICROSECOND('12:00:00.123456'); -> 123456 mysql> SELECT MICROSECOND('2009-12-31 23:59:59.000010'); -> 10 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" CONSTRAINT&InnoDB supports foreign key constraints. The syntax for a foreign key constraint definition in InnoDB looks like this: [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name, ...) REFERENCES tbl_name (index_col_name,...) [ON DELETE reference_option] [ON UPDATE reference_option] reference_option: RESTRICT | CASCADE | SET NULL | NO ACTION URL: http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html CREATE TABLE product (category INT NOT NULL, id INT NOT NULL, price DECIMAL, PRIMARY KEY(category, id)) ENGINE=INNODB; CREATE TABLE customer (id INT NOT NULL, PRIMARY KEY (id)) ENGINE=INNODB; CREATE TABLE product_order (no INT NOT NULL AUTO_INCREMENT, product_category INT NOT NULL, product_id INT NOT NULL, customer_id INT NOT NULL, PRIMARY KEY(no), INDEX (product_category, product_id), FOREIGN KEY (product_category, product_id) REFERENCES product(category, id) ON UPDATE CASCADE ON DELETE RESTRICT, INDEX (customer_id), FOREIGN KEY (customer_id) REFERENCES customer(id)) ENGINE=INNODB; Jhttp://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.htmlP" CREATE SERVER&Syntax: CREATE SERVER server_name FOREIGN DATA WRAPPER wrapper_name OPTIONS (option [, option] ...) option: { HOST character-literal | DATABASE character-literal | USER character-literal | PASSWORD character-literal | SOCKET character-literal | OWNER character-literal | PORT numeric-literal } This statement creates the definition of a server for use with the FEDERATED storage engine. The CREATE SERVER statement creates a new row within the servers table within the mysql database. This statement requires the SUPER privilege. The server_name should be a unique reference to the server. Server definitions are global within the scope of the server, it is not possible to qualify the server definition to a specific database. server_name has a maximum length of 64 characters (names longer than 64 characters are silently truncated), and is case insensitive. You may specify the name as a quoted string. The wrapper_name should be mysql, and may be quoted with single quotes. Other values for wrapper_name are not currently supported. For each option you must specify either a character literal or numeric literal. Character literals are UTF-8, support a maximum length of 64 characters and default to a blank (empty) string. String literals are silently truncated to 64 characters. Numeric literals must be a number between 0 and 9999, default value is 0. *Note*: Note that the OWNER option is currently not applied, and has no effect on the ownership or operation of the server connection that is created. The CREATE SERVER statement creates an entry in the mysql.server table that can later be used with the CREATE TABLE statement when creating a FEDERATED table. The options that you specify will be used to populate the columns in the mysql.server table. The table columns are Server_name, Host, Db, Username, Password, Port and Socket. URL: http://dev.mysql.com/doc/refman/5.1/en/create-server.html kCREATE SERVER s FOREIGN DATA WRAPPER mysql OPTIONS (USER 'Remote', HOST '192.168.1.106', DATABASE 'test'); 9http://dev.mysql.com/doc/refman/5.1/en/create-server.html"FIELD$Syntax: FIELD(str,str1,str2,str3,...) Returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found. If all arguments to FIELD() are strings, all arguments are compared as strings. If all arguments are numbers, they are compared as numbers. Otherwise, the arguments are compared as double. If str is NULL, the return value is 0 because NULL fails equality comparison with any value. FIELD() is the complement of ELT(). URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT FIELD('ej', 'Hej', 'ej', 'Heja', 'hej', 'foo'); -> 2 mysql> SELECT FIELD('fo', 'Hej', 'ej', 'Heja', 'hej', 'foo'); -> 0 SELECT MAKETIME(12,15,30); -> '12:15:30' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html"CURDATESyntax: CURDATE() Returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context. URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html bmysql> SELECT CURDATE(); -> '2008-06-13' mysql> SELECT CURDATE() + 0; -> 20080613 Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.htmlw2 SET PASSWORD (Syntax: SET PASSWORD [FOR user] = { PASSWORD('some password') | OLD_PASSWORD('some password') | 'encrypted password' } The SET PASSWORD statement assigns a password to an existing MySQL user account. If the password is specified using the PASSWORD() or OLD_PASSWORD() function, the literal text of the password should be given. If the password is specified without using either function, the password should be the already-encrypted password value as returned by PASSWORD(). With no FOR clause, this statement sets the password for the current user. Any client that has connected to the server using a non-anonymous account can change the password for that account. With a FOR clause, this statement sets the password for a specific account on the current server host. Only clients that have the UPDATE privilege for the mysql database can do this. The user value should be given in user_name@host_name format, where user_name and host_name are exactly as they are listed in the User and Host columns of the mysql.user table entry. For example, if you had an entry with User and Host column values of 'bob' and '%.loc.gov', you would write the statement like this: SET PASSWORD FOR 'bob'@'%.loc.gov' = PASSWORD('newpass'); URL: http://dev.mysql.com/doc/refman/5.1/en/set-password.html 8http://dev.mysql.com/doc/refman/5.1/en/set-password.html ?2ALTER TABLESPACE& Syntax: ALTER TABLESPACE tablespace_name {ADD|DROP} DATAFILE 'file_name' [INITIAL_SIZE [=] size] [WAIT] ENGINE [=] engine_name This statement can be used either to add a new data file, or to drop a data file from a tablespace. The ADD DATAFILE variant allows you to specify an initial size using an INITIAL_SIZE clause, where size is measured in bytes; the default value is 128M (128 megabytes). You may optionally follow this integer value with a one-letter abbreviation for an order of magnitude, similar to those used in my.cnf. Generally, this is one of the letters M (for megabytes) or G (for gigabytes). On 32-bit systems, the maximum supported value for INITIAL_SIZE is 4G. (Bug#29186 (http://bugs.mysql.com/29186)) Once a data file has been created, its size cannot be changed; however, you can add more data files to the tablespace using additional ALTER TABLESPACE ... ADD DATAFILE statements. Using DROP DATAFILE with ALTER TABLESPACE drops the data file 'file_name' from the tablespace. This file must already have been added to the tablespace using CREATE TABLESPACE or ALTER TABLESPACE; otherwise an error will result. Both ALTER TABLESPACE ... ADD DATAFILE and ALTER TABLESPACE ... DROP DATAFILE require an ENGINE clause which specifies the storage engine used by the tablespace. In MySQL 5.1, the only accepted values for engine_name are NDB and NDBCLUSTER. WAIT is parsed but otherwise ignored, and so has no effect in MySQL 5.1. It is intended for future expansion. When ALTER TABLESPACE ... ADD DATAFILE is used with ENGINE = NDB, a data file is created on each Cluster data node. You can verify that the data files were created and obtain information about them by querying the INFORMATION_SCHEMA.FILES table. For example, the following query shows all data files belonging to the tablespace named newts: mysql> SELECT LOGFILE_GROUP_NAME, FILE_NAME, EXTRA -> FROM INFORMATION_SCHEMA.FILES -> WHERE TABLESPACE_NAME = 'newts' AND FILE_TYPE = 'DATAFILE'; +--------------------+--------------+----------------+ | LOGFILE_GROUP_NAME | FILE_NAME | EXTRA | +--------------------+--------------+----------------+ | lg_3 | newdata.dat | CLUSTER_NODE=3 | | lg_3 | newdata.dat | CLUSTER_NODE=4 | | lg_3 | newdata2.dat | CLUSTER_NODE=3 | | lg_3 | newdata2.dat | CLUSTER_NODE=4 | +--------------------+--------------+----------------+ 2 rows in set (0.03 sec) See http://dev.mysql.com/doc/refman/5.1/en/files-table.html. ALTER TABLESPACE was added in MySQL 5.1.6. In MySQL 5.1, it is useful only with Disk Data storage for MySQL Cluster. See http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-disk-data.html. URL: http://dev.mysql.com/doc/refman/5.1/en/alter-tablespace.html 0 and expr1 <> NULL) then IF() returns expr2; otherwise it returns expr3. IF() returns a numeric or string value, depending on the context in which it is used. URL: http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html mysql> SELECT IF(1>2,2,3); -> 3 mysql> SELECT IF(1<2,'yes','no'); -> 'yes' mysql> SELECT IF(STRCMP('test','test1'),'no','yes'); -> 'no' Bhttp://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html-"DATABASESyntax: DATABASE() Returns the default (current) database name as a string in the utf8 character set. If there is no default database, DATABASE() returns NULL. Within a stored routine, the default database is the database that the routine is associated with, which is not necessarily the same as the database that is the default in the calling context. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html ,mysql> SELECT DATABASE(); -> 'test' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html#2 POINTFROMWKB PointFromWKB(wkb[,srid]) Constructs a POINT value using its WKB representation and SRID. URL: http://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions Uhttp://dev.mysql.com/doc/refman/5.1/en/creating-spatial-values.html#gis-wkb-functions2POWER{Syntax: POWER(X,Y) This is a synonym for POW(). URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlY"ATANSyntax: ATAN(X) Returns the arc tangent of X, that is, the value whose tangent is X. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html fmysql> SELECT ATAN(2); -> 1.1071487177941 mysql> SELECT ATAN(-2); -> -1.1071487177941 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html"STRCMP$Syntax: STRCMP(expr1,expr2) STRCMP() returns 0 if the strings are the same, -1 if the first argument is smaller than the second according to the current sort order, and 1 otherwise. URL: http://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html mysql> SELECT STRCMP('text', 'text2'); -> -1 mysql> SELECT STRCMP('text2', 'text'); -> 1 mysql> SELECT STRCMP('text', 'text'); -> 0 Ghttp://dev.mysql.com/doc/refman/5.1/en/string-comparison-functions.html 2INSERT DELAYEDw Syntax: INSERT DELAYED ... The DELAYED option for the INSERT statement is a MySQL extension to standard SQL that is very useful if you have clients that cannot or need not wait for the INSERT to complete. This is a common situation when you use MySQL for logging and you also periodically run SELECT and UPDATE statements that take a long time to complete. When a client uses INSERT DELAYED, it gets an okay from the server at once, and the row is queued to be inserted when the table is not in use by any other thread. Another major benefit of using INSERT DELAYED is that inserts from many clients are bundled together and written in one block. This is much faster than performing many separate inserts. Note that INSERT DELAYED is slower than a normal INSERT if the table is not otherwise in use. There is also the additional overhead for the server to handle a separate thread for each table for which there are delayed rows. This means that you should use INSERT DELAYED only when you are really sure that you need it. The queued rows are held only in memory until they are inserted into the table. This means that if you terminate mysqld forcibly (for example, with kill -9) or if mysqld dies unexpectedly, any queued rows that have not been written to disk are lost. There are some constraints on the use of DELAYED: o INSERT DELAYED works only with MyISAM, MEMORY, ARCHIVE, and (as of MySQL 5.1.19) BLACKHOLE tables. See http://dev.mysql.com/doc/refman/5.1/en/myisam-storage-engine.html, http://dev.mysql.com/doc/refman/5.1/en/memory-storage-engine.html, http://dev.mysql.com/doc/refman/5.1/en/archive-storage-engine.html, and http://dev.mysql.com/doc/refman/5.1/en/blackhole-storage-engine.html. o For MyISAM tables, if there are no free blocks in the middle of the data file, concurrent SELECT and INSERT statements are supported. Under these circumstances, you very seldom need to use INSERT DELAYED with MyISAM. o INSERT DELAYED should be used only for INSERT statements that specify value lists. The server ignores DELAYED for INSERT ... SELECT or INSERT ... ON DUPLICATE KEY UPDATE statements. o Because the INSERT DELAYED statement returns immediately, before the rows are inserted, you cannot use LAST_INSERT_ID() to get the AUTO_INCREMENT value that the statement might generate. o DELAYED rows are not visible to SELECT statements until they actually have been inserted. o DELAYED is ignored on slave replication servers, so that INSERT DELAYED is treated as a normal INSERT on slaves. This is because DELAYED could cause the slave to have different data than the master. o Pending INSERT DELAYED statements are lost if a table is write locked and ALTER TABLE is used to modify the table structure. o INSERT DELAYED is not supported for views. o INSERT DELAYED is not supported for partitioned tables. URL: http://dev.mysql.com/doc/refman/5.1/en/insert-delayed.html :http://dev.mysql.com/doc/refman/5.1/en/insert-delayed.html]"SHOW PROCEDURE CODE=Syntax: SHOW {PROCEDURE | FUNCTION} CODE sp_name These statements are MySQL extensions that are available only for servers that have been built with debugging support. They display a representation of the internal implementation of the named routine. The statements require that you be the owner of the routine or have SELECT access to the mysql.proc table. If the named routine is available, each statement produces a result set. Each row in the result set corresponds to one "instruction" in the routine. The first column is Pos, which is an ordinal number beginning with 0. The second column is Instruction, which contains an SQL statement (usually changed from the original source), or a directive which has meaning only to the stored-routine handler. URL: http://dev.mysql.com/doc/refman/5.1/en/show-procedure-code.html mysql> DELIMITER // mysql> CREATE PROCEDURE p1 () -> BEGIN -> DECLARE fanta INT DEFAULT 55; -> DROP TABLE t2; -> LOOP -> INSERT INTO t3 VALUES (fanta); -> END LOOP; -> END// Query OK, 0 rows affected (0.00 sec) mysql> SHOW PROCEDURE CODE p1// +-----+----------------------------------------+ | Pos | Instruction | +-----+----------------------------------------+ | 0 | set fanta@0 55 | | 1 | stmt 9 "DROP TABLE t2" | | 2 | stmt 5 "INSERT INTO t3 VALUES (fanta)" | | 3 | jump 2 | +-----+----------------------------------------+ 4 rows in set (0.00 sec) ?http://dev.mysql.com/doc/refman/5.1/en/show-procedure-code.html2 MEDIUMTEXTMEDIUMTEXT [CHARACTER SET charset_name] [COLLATE collation_name] A TEXT column with a maximum length of 16,777,215 (224 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. Each MEDIUMTEXT value is stored using a three-byte length prefix that indicates the number of bytes in the value. URL: http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html @http://dev.mysql.com/doc/refman/5.1/en/string-type-overview.html"LNSyntax: LN(X) Returns the natural logarithm of X; that is, the base-e logarithm of X. If X is less than or equal to 0, then NULL is returned. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Wmysql> SELECT LN(2); -> 0.69314718055995 mysql> SELECT LN(-2); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2RETURNSyntax: RETURN expr The RETURN statement terminates execution of a stored function and returns the value expr to the function caller. There must be at least one RETURN statement in a stored function. There may be more than one if the function has multiple exit points. This statement is not used in stored procedures, triggers, or events. URL: http://dev.mysql.com/doc/refman/5.1/en/return.html 2http://dev.mysql.com/doc/refman/5.1/en/return.htmlW2SHOW COLLATIONSyntax: SHOW COLLATION [LIKE 'pattern' | WHERE expr] The output from SHOW COLLATION includes all available character sets. The LIKE clause, if present, indicates which collation names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in http://dev.mysql.com/doc/refman/5.1/en/extended-show.html. For example: mysql> SHOW COLLATION LIKE 'latin1%'; +-------------------+---------+----+---------+----------+---------+ | Collation | Charset | Id | Default | Compiled | Sortlen | +-------------------+---------+----+---------+----------+---------+ | latin1_german1_ci | latin1 | 5 | | | 0 | | latin1_swedish_ci | latin1 | 8 | Yes | Yes | 0 | | latin1_danish_ci | latin1 | 15 | | | 0 | | latin1_german2_ci | latin1 | 31 | | Yes | 2 | | latin1_bin | latin1 | 47 | | Yes | 0 | | latin1_general_ci | latin1 | 48 | | | 0 | | latin1_general_cs | latin1 | 49 | | | 0 | | latin1_spanish_ci | latin1 | 94 | | | 0 | +-------------------+---------+----+---------+----------+---------+ URL: http://dev.mysql.com/doc/refman/5.1/en/show-collation.html :http://dev.mysql.com/doc/refman/5.1/en/show-collation.html"LOGFSyntax: LOG(X), LOG(B,X) If called with one parameter, this function returns the natural logarithm of X. If X is less than or equal to 0, then NULL is returned. The inverse of this function (when called with a single argument) is the EXP() function. URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html Ymysql> SELECT LOG(2); -> 0.69314718055995 mysql> SELECT LOG(-2); -> NULL Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html2SET SQL_LOG_BIN@Syntax: SET SQL_LOG_BIN = {0|1} Disables or enables binary logging for the current connection (SQL_LOG_BIN is a session variable) if the client has the SUPER privilege. The statement is refused with an error if the client does not have that privilege. URL: http://dev.mysql.com/doc/refman/5.1/en/set-sql-log-bin.html ;http://dev.mysql.com/doc/refman/5.1/en/set-sql-log-bin.html6"!=cSyntax: <>, != Not equal: URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html mysql> SELECT '.01' <> '0.01'; -> 1 mysql> SELECT .01 <> '0.01'; -> 0 mysql> SELECT 'zapp' <> 'zappp'; -> 1 @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html"WHILESyntax: [begin_label:] WHILE search_condition DO statement_list END WHILE [end_label] The statement list within a WHILE statement is repeated as long as the search_condition is true. statement_list consists of one or more statements. A WHILE statement can be labeled. end_label cannot be given unless begin_label also is present. If both are present, they must be the same. URL: http://dev.mysql.com/doc/refman/5.1/en/while-statement.html ~CREATE PROCEDURE dowhile() BEGIN DECLARE v1 INT DEFAULT 5; WHILE v1 > 0 DO ... SET v1 = v1 - 1; END WHILE; END ;http://dev.mysql.com/doc/refman/5.1/en/while-statement.htmlk2 AES_DECRYPT Syntax: AES_DECRYPT(crypt_str,key_str) This function allows decryption of data using the official AES (Advanced Encryption Standard) algorithm. For more information, see the description of AES_ENCRYPT(). URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html @http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html"DAYNAME=Syntax: DAYNAME(date) Returns the name of the weekday for date. As of MySQL 5.1.12, the language used for the name is controlled by the value of the lc_time_names system variable (http://dev.mysql.com/doc/refman/5.1/en/locale-support.html). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html ;mysql> SELECT DAYNAME('2007-02-03'); -> 'Saturday' Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html" COERCIBILITYSyntax: COERCIBILITY(str) Returns the collation coercibility value of the string argument. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html mysql> SELECT COERCIBILITY('abc' COLLATE latin1_swedish_ci); -> 0 mysql> SELECT COERCIBILITY(USER()); -> 3 mysql> SELECT COERCIBILITY('abc'); -> 4 Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html%2INTINT[(M)] [UNSIGNED] [ZEROFILL] A normal-size integer. The signed range is -2147483648 to 2147483647. The unsigned range is 0 to 4294967295. URL: http://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.html Ahttp://dev.mysql.com/doc/refman/5.1/en/numeric-type-overview.htmlT"GLENGTH GLength(ls) Returns as a double-precision number the length of the LineString value ls in its associated spatial reference. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functions mysql> SET @ls = 'LineString(1 1,2 2,3 3)'; mysql> SELECT GLength(GeomFromText(@ls)); +----------------------------+ | GLength(GeomFromText(@ls)) | +----------------------------+ | 2.8284271247462 | +----------------------------+ ehttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#linestring-property-functionsP"RADIANSSyntax: RADIANS(X) Returns the argument X, converted from degrees to radians. (Note that π radians equals 180 degrees.) URL: http://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.html 6mysql> SELECT RADIANS(90); -> 1.5707963267949 Bhttp://dev.mysql.com/doc/refman/5.1/en/mathematical-functions.htmlg" COLLATIONSyntax: COLLATION(str) Returns the collation of the string argument. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html mysql> SELECT COLLATION('abc'); -> 'latin1_swedish_ci' mysql> SELECT COLLATION(_utf8'abc'); -> 'utf8_general_ci' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.htmlv"COALESCESyntax: COALESCE(value,...) Returns the first non-NULL value in the list, or NULL if there are no non-NULL values. URL: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html emysql> SELECT COALESCE(NULL,1); -> 1 mysql> SELECT COALESCE(NULL,NULL,NULL); -> NULL @http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.htmlI"VERSIONSyntax: VERSION() Returns a string that indicates the MySQL server version. The string uses the utf8 character set. URL: http://dev.mysql.com/doc/refman/5.1/en/information-functions.html 6mysql> SELECT VERSION(); -> '5.1.30-standard' Ahttp://dev.mysql.com/doc/refman/5.1/en/information-functions.html"MAKE_SET$vSyntax: MAKE_SET(bits,str1,str2,...) Returns a set value (a string containing substrings separated by "," characters) consisting of the strings that have the corresponding bit in bits set. str1 corresponds to bit 0, str2 to bit 1, and so on. NULL values in str1, str2, ... are not appended to the result. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html mysql> SELECT MAKE_SET(1,'a','b','c'); -> 'a' mysql> SELECT MAKE_SET(1 | 4,'hello','nice','world'); -> 'hello,world' mysql> SELECT MAKE_SET(1 | 4,'hello','nice',NULL,'world'); -> 'hello' mysql> SELECT MAKE_SET(0,'a','b','c'); -> '' SELECT FIND_IN_SET('b','a,b,c,d'); -> 2