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https://dev.mysql.com/doc/refman/8.4/en/information-schema-partitions-table.html
SUBPARTITION_NAME If the PARTITIONS table row represents a subpartition, the name of subpartition; otherwise NULL. For partitions whose PARTITION_METHOD is other than RANGE or LIST, this column is always NULL. However, the values of the ...Each row ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-columns.html
Invisible columns support the usual column attributes: NULL, NOT NULL, AUTO_INCREMENT, and so forth. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `col1` int DEFAULT NULL, `col2` int DEFAULT NULL ) ENGINE=InnoDB DEFAULT ...An invisible column is normally hidden to queries, but can be accessed if explicitly ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-transactions-current-table.html
END_EVENT_ID This column is set to NULL when the event starts and updated to the thread current event number when the event ends. If an event is produced from an instrument that has TIMED = NO, timing information is not collected, and TIMER_START, ...The table stores one row per thread showing the current status of the thread's most recent monitored transaction event, so there is no system variable for configuring the table ...
https://dev.mysql.com/doc/refman/8.4/en/rewriter-query-rewrite-plugin-usage.html
row *************************** id: 1 pattern: SELECT ? pattern_database: NULL replacement: SELECT ? + 1 enabled: YES message: NULL pattern_digest: NULL normalized_pattern: NULL The rule specifies a pattern template indicating which SELECT ... To ...
https://dev.mysql.com/doc/refman/8.4/en/selecting-all.html
For example, you may happen to think that the birth date for Bowser doesn't seem quite right. Consulting your original pedigree papers, you find that the correct birth year should be 1989, not 1979. Fix only the erroneous record with an UPDATE ...
https://dev.mysql.com/doc/refman/8.4/en/selecting-rows.html
As shown in the preceding section, it is easy to retrieve an entire table. But typically you don't want to see the entire table, particularly when it becomes large. Instead, you're usually more interested in answering a particular question, in ...
https://dev.mysql.com/doc/refman/8.4/en/show-events.html
row *************************** Db: myschema Name: e_daily Definer: jon@ghidora Time zone: SYSTEM Type: RECURRING Execute at: NULL Interval value: 1 Interval field: DAY Starts: 2018-08-08 11:06:34 Ends: NULL Status: ENABLED Originator: 1 ... SHOW ...
https://dev.mysql.com/doc/refman/8.4/en/tracing-example.html
(Observe that it could have a match, were the operator a null-safe equals <=>). Now we can examine the trace, whose first column (QUERY), containing the original statement to be traced, is shown here: SELECT * FROM ...
https://dev.mysql.com/doc/refman/8.4/en/xml-functions.html
If any of the arguments to UpdateXML() are NULL, the function returns NULL. Table 14.16 XML Functions Name Description ExtractValue() Extract a value from an XML string using XPath notation UpdateXML() Return replaced XML fragment This section ...
https://dev.mysql.com/doc/c-api/8.4/en/c-api-prepared-statement-data-structures.html
bool *is_null This member points to a bool variable that is true if a value is NULL, false if it is not NULL. For input, set *is_null to true to indicate that you are passing a NULL value as a statement parameter. is_null is a pointer to a boolean ... Prepared statements use several data structures: To obtain a statement handler, pass a MYSQL connection handler to mysql_stmt_init(), which returns a pointer to a MYSQL_STMT data ...