https://dev.mysql.com/innodb-memcached-porting-mysql.html
Consider these aspects of memcached applications when adapting an existing MySQL schema or application to use the daemon_memcached plugin: memcached keys cannot contain spaces or newlines, because these characters are used as separators in the ...
https://dev.mysql.com/keyring-udfs-general-purpose.html
If the key cannot be created, the return value is NULL and an error occurs. mysql> SELECT @x; +------+ | @x | +------+ | NULL | +------+ mysql> SELECT keyring_key_generate('x', 'AES', 16) INTO @x; mysql> SELECT @x; +------+ | @x | +------+ | 1 | ...
https://dev.mysql.com/partitioning-limitations.html
However, the result must be an integer value or NULL (except in the case of [LINEAR] KEY partitioning, as discussed elsewhere in this chapter; see Section 23.2, “Partitioning Types”, for more information). As discussed elsewhere, handling of ...
https://dev.mysql.com/performance-schema-quick-start.html
row *************************** Table: setup_consumers Create Table: CREATE TABLE `setup_consumers` ( `NAME` varchar(64) NOT NULL, `ENABLED` enum('YES','NO') NOT NULL, PRIMARY KEY (`NAME`) ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8mb4 ... This ...
https://dev.mysql.com/regexp.html
If expr or pat is NULL, the return value is NULL. If expr or pat is NULL, the return value is NULL. If expr or pat is NULL, the return value is NULL. If expr, pat, or repl is NULL, the return value is NULL. If expr or pat is NULL, the return value ...This section discusses the functions and operators available for regular expression matching and illustrates, with examples, some of the special characters and constructs that can be used for regular expression ...
https://dev.mysql.com/show-columns.html
Collation The collation for nonbinary string columns, or NULL for other columns. The value is YES if NULL values can be stored in the column, NO if not. (A UNIQUE index permits multiple NULL values, but you can tell whether the column permits NULL ... SHOW [EXTENDED] [FULL] {COLUMNS | FIELDS} {FROM | IN} tbl_name [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW COLUMNS displays information about the columns in a given ...
https://dev.mysql.com/audit-log-reference.html
Return value: The password string for success (up to 766 bytes), or NULL and an error for failure. Each event in the return value is a JSON hash, except that the last array element may be a JSON null value to indicate no following events are ...
https://dev.mysql.com/data-type-defaults.html
In the definition of an integer column, it is an alias for NOT NULL AUTO_INCREMENT UNIQUE. If a data type specification includes no explicit DEFAULT value, MySQL determines the default value as follows: If the column can take NULL as a value, the ...
https://dev.mysql.com/events-table.html
If the event's timing is determined by an EVERY clause instead of an AT clause (that is, if the event is recurring), the value of this column is NULL. This is displayed as a DATETIME value, and is NULL if no start date and time are defined for the ... The EVENTS table provides information about Event Manager events, which are discussed in Section 24.4, “Using the Event ...
https://dev.mysql.com/getting-information.html
To find out which database is currently selected, use the DATABASE() function: mysql> SELECT DATABASE(); +------------+ | DATABASE() | +------------+ | menagerie | +------------+ If you have not yet selected any database, the result is NULL. What ...
