https://dev.mysql.com/data-locks-table.html
row *************************** ENGINE: INNODB ENGINE_LOCK_ID: 139664434886512:1059:139664350547912 ENGINE_TRANSACTION_ID: 2569 THREAD_ID: 46 EVENT_ID: 12 OBJECT_SCHEMA: test OBJECT_NAME: t1 PARTITION_NAME: NULL SUBPARTITION_NAME: NULL INDEX_NAME: ...For information about which lock requests are blocked by which held locks, see Section 26.12.12.2, “The data_lock_waits ...
https://dev.mysql.com/events-statements-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 statement event, so there is no system variable for configuring the table ...
https://dev.mysql.com/json-creation-functions.html
mysql> SELECT JSON_ARRAY(1, "abc", NULL, TRUE, CURTIME()); +---------------------------------------------+ | JSON_ARRAY(1, "abc", NULL, TRUE, CURTIME()) | +---------------------------------------------+ | [1, "abc", null, true, "11:30:24.000000"] | ... The functions listed in this section compose JSON values from component ...
https://dev.mysql.com/mysql-fetch-row.html
mysql_fetch_row() retrieves the next row of a result set: When used after mysql_store_result() or mysql_store_result_nonblocking(), mysql_fetch_row() returns NULL if there are no more rows to retrieve. When used after mysql_use_result(), ...Its ...
https://dev.mysql.com/mysql-real-connect.html
The client attempts to connect as follows: If host is NULL or the string "localhost", a connection to the local host is assumed: On Windows, the client connects using a shared-memory connection, if the server has shared-memory connections enabled.
https://dev.mysql.com/show-processlist.html
row *************************** Id: 1 User: system user Host: db: NULL Command: Connect Time: 1030455 State: Waiting for master to send event Info: NULL *************************** 2. row *************************** Id: 2 User: system user Host: db: ... SHOW [FULL] PROCESSLIST SHOW PROCESSLIST shows which threads are ...
https://dev.mysql.com/trigger-syntax.html
To create a trigger or drop a trigger, use the CREATE TRIGGER or DROP TRIGGER statement, described in Section 13.1.22, “CREATE TRIGGER Syntax”, and Section 13.1.34, “DROP TRIGGER Syntax”. Here is a simple example that associates a trigger ...
https://dev.mysql.com/column-count-limit.html
mysql> CREATE TABLE t2 (c1 VARCHAR(65533) NOT NULL) ENGINE = InnoDB CHARACTER SET latin1; Query OK, 0 rows affected (0.01 sec) For MyISAM tables, NULL columns require additional space in the row to record whether their values are NULL. Each NULL ...
https://dev.mysql.com/create-table-secondary-indexes.html
row *************************** id: 1 select_type: SIMPLE table: jemp partitions: NULL type: range possible_keys: i key: i key_len: 5 ref: NULL rows: 2 filtered: 100.00 Extra: Using where 1 row in set, 1 warning (0.00 sec) mysql> SHOW WARNINGS\G ...
https://dev.mysql.com/enum.html
Creating and Using ENUM Columns Index Values for Enumeration Literals Handling of Enumeration Literals Empty or NULL Enumeration Values Enumeration Sorting Enumeration Limitations An enumeration value must be a quoted string literal. This means that ... An ENUM is a string object with a value chosen from a list of permitted values that are enumerated explicitly in the column specification at table creation ...
