我们如何检查数据库中所有触发器的列表？
借助SHOWTRIGGERS语句，我们可以列出特定数据库中的所有触发器。可以通过以下示例进行说明-
示例
mysql> Show Triggers\G
*************************** 1. row ***************************
Trigger: trigger_before_delete_sample
Event: DELETE
Table: sample
Statement: BEGIN
SET @count = if (@count IS NULL, 1, (@count+1));
INSERT INTO sample_rowaffected values (@count);
END
Timing: BEFORE
Created: 2017-11-21 12:31:58.70
sql_mode:
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERR
OR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
Definer: root@localhost
character_set_client: cp850
collation_connection: cp850_general_ci
Database Collation: latin1_swedish_ci
*************************** 2. row ***************************
Trigger: before_inser_studentage
Event: INSERT
Table: student_age
Statement: IF NEW.age < 0 THEN SET NEW.age = 0;
END IF
Timing: BEFORE
Created: 2017-11-21 11:26:15.34
sql_mode:
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERR
OR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
Definer: root@localhost
character_set_client: cp850
collation_connection: cp850_general_ci
Database Collation: latin1_swedish_ci
2 rows in set (0.01 sec)上面的结果集提供了当前数据库中的触发器列表。现在，如果我们想获取特定数据库中的触发器列表，则可以使用以下语句-
mysql> Show Triggers from tutorials\G Empty set (0.00 sec)
上面的结果集表明，名为“tutorials”的数据库中没有触发器。