https://dev.mysql.com/audit-log-logging-configuration.html
| +-----------------------------------------------------------------------+ Each event in the audit_log_read() return value is a JSON hash, except that the last array element may be a JSON null value to indicate no following events are available to ... This section describes how to configure audit logging characteristics, such as the file to which the audit log plugin writes events, the format of written events, and whether to enable log file compression and ...
https://dev.mysql.com/charset-unicode-conversion.html
This section describes issues that you may face when converting character data between the utf8mb3 and utf8mb4 character sets. Note This discussion focuses primarily on converting between utf8mb3 and utf8mb4, but similar principles apply to ...
https://dev.mysql.com/counting-rows.html
Counting the total number of animals you have is the same question as “How many rows are in the pet table?” because there is one record per pet. COUNT(*) counts the number of rows, so the query to count your animals looks like this: mysql> ...
https://dev.mysql.com/create-table-check-constraints.html
expr specifies the constraint condition as a boolean expression that must evaluate to TRUE or UNKNOWN (for NULL values) for each row of the table. Prior to MySQL 8.0.16, CREATE TABLE permits only the following limited version of table CHECK ...
https://dev.mysql.com/data-size.html
It makes SQL operations faster, by enabling better use of indexes and eliminating overhead for testing whether each value is NULL. If you really need NULL values in your tables, use them. Just avoid the default setting that allows NULL values in ...
https://dev.mysql.com/datetime.html
This section describes their characteristics, how they are similar, and how they differ. MySQL recognizes DATE, DATETIME, and TIMESTAMP values in several formats, described in Section 9.1.3, “Date and Time Literals”. For the DATE and DATETIME ...
https://dev.mysql.com/events-configuration.html
row *************************** Id: 1 User: root Host: localhost db: NULL Command: Query Time: 0 State: NULL Info: show processlist *************************** 2. row *************************** Id: 2 User: event_scheduler Host: localhost db: NULL ... Events are executed by a special event scheduler thread; when we refer to the Event Scheduler, we actually refer to this ...
https://dev.mysql.com/explain-extended.html
row *************************** id: 1 select_type: PRIMARY table: t1 type: index possible_keys: NULL key: PRIMARY key_len: 4 ref: NULL rows: 4 filtered: 100.00 Extra: Using index *************************** 2. row *************************** id: 2 ... The EXPLAIN statement produces extra (“extended”) information that is not part of EXPLAIN output but can be viewed by issuing a SHOW WARNINGS statement following ...
https://dev.mysql.com/gis-wkb-functions.html
Unless otherwise specified, functions in this section handle their arguments as follows: If the WKB or SRID argument is NULL, the return value is NULL. If the options argument is NULL, the return value is NULL. These functions take as arguments a ...
https://dev.mysql.com/group-by-handling.html
The query is invalid if name is not a primary key of t or a unique NOT NULL column. SQL-92 and earlier does not permit queries for which the select list, HAVING condition, or ORDER BY list refer to nonaggregated columns that are not named in the ...
