数据库触发器详解(2)

 
Mysql中有一个information_schema.TRIGGERS表，存储所有库中的所有触发器，desc information_schema. TRIGGERS，可以看到表结构：
 
+----------------------------+--------------+------+-----+---------+-------+
| Field                      | Type         | Null | Key | Default | Extra |
+----------------------------+--------------+------+-----+---------+-------+
| TRIGGER_CATALOG            | varchar(512) | YES |     | NULL    |       |
| TRIGGER_SCHEMA             | varchar(64) | NO   |     |         |       |
| TRIGGER_NAME               | varchar(64) | NO   |     |         |       |
| EVENT_MANIPULATION         | varchar(6)   | NO   |     |         |       |
| EVENT_OBJECT_CATALOG       | varchar(512) | YES |     | NULL    |       |
| EVENT_OBJECT_SCHEMA        | varchar(64) | NO   |     |         |       |
| EVENT_OBJECT_TABLE         | varchar(64) | NO   |     |         |       |
| ACTION_ORDER               | bigint(4)    | NO   |     | 0       |       |
| ACTION_CONDITION           | longtext     | YES |     | NULL    |       |
| ACTION_STATEMENT           | longtext     | NO   |     |         |       |
| ACTION_ORIENTATION         | varchar(9)   | NO   |     |         |       |
| ACTION_TIMING              | varchar(6)   | NO   |     |         |       |