28.3.44 The INFORMATION_SCHEMA TRIGGERS Table

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MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4

28.3.44 The INFORMATION_SCHEMA TRIGGERS Table

The TRIGGERS table provides information about triggers. To see information about a table's triggers, you must have the TRIGGER privilege for the table.

The TRIGGERS table has these columns:

• TRIGGER_CATALOG

The name of the catalog to which the trigger belongs. This value is always def. - TRIGGER_SCHEMA

The name of the schema (database) to which the trigger belongs. - TRIGGER_NAME

The name of the trigger. - EVENT_MANIPULATION

The trigger event. This is the type of operation on the associated table for which the trigger activates. The value is INSERT (a row was inserted), DELETE (a row was deleted), or UPDATE (a row was modified). - EVENT_OBJECT_CATALOG, EVENT_OBJECT_SCHEMA, and EVENT_OBJECT_TABLE

As noted in Section 27.3, “Using Triggers”, every trigger is associated with exactly one table. These columns indicate the catalog and schema (database) in which this table occurs, and the table name, respectively. The EVENT_OBJECT_CATALOG value is always def. - ACTION_ORDER

The ordinal position of the trigger's action within the list of triggers on the same table with the same EVENT_MANIPULATION and ACTION_TIMING values. - ACTION_CONDITION

This value is always NULL. - ACTION_STATEMENT

The trigger body; that is, the statement executed when the trigger activates. This text uses UTF-8 encoding. - ACTION_ORIENTATION

This value is always ROW. - ACTION_TIMING

Whether the trigger activates before or after the triggering event. The value is BEFORE or AFTER. - ACTION_REFERENCE_OLD_TABLE

This value is always NULL. - ACTION_REFERENCE_NEW_TABLE

This value is always NULL. - ACTION_REFERENCE_OLD_ROW and ACTION_REFERENCE_NEW_ROW

The old and new column identifiers, respectively. The ACTION_REFERENCE_OLD_ROW value is always OLD and the ACTION_REFERENCE_NEW_ROW value is always NEW. - CREATED

The date and time when the trigger was created. This is a TIMESTAMP(2) value (with a fractional part in hundredths of seconds) for triggers. - SQL_MODE

The SQL mode in effect when the trigger was created, and under which the trigger executes. For the permitted values, see Section 7.1.11, “Server SQL Modes”. - DEFINER

The account named in the DEFINER clause (often the user who created the trigger), in 'user_name'@'host_name' format. - CHARACTER_SET_CLIENT

The session value of the character_set_client system variable when the trigger was created. - COLLATION_CONNECTION

The session value of the collation_connection system variable when the trigger was created. - DATABASE_COLLATION

The collation of the database with which the trigger is associated.

Example

The following example uses the ins_sum trigger defined in Section 27.3, “Using Triggers”:

mysql> SELECT * FROM INFORMATION_SCHEMA.TRIGGERS
       WHERE TRIGGER_SCHEMA='test' AND TRIGGER_NAME='ins_sum'\G
*************************** 1. row ***************************
           TRIGGER_CATALOG: def
            TRIGGER_SCHEMA: test
              TRIGGER_NAME: ins_sum
        EVENT_MANIPULATION: INSERT
      EVENT_OBJECT_CATALOG: def
       EVENT_OBJECT_SCHEMA: test
        EVENT_OBJECT_TABLE: account
              ACTION_ORDER: 1
          ACTION_CONDITION: NULL
          ACTION_STATEMENT: SET @sum = @sum + NEW.amount
        ACTION_ORIENTATION: ROW
             ACTION_TIMING: BEFORE
ACTION_REFERENCE_OLD_TABLE: NULL
ACTION_REFERENCE_NEW_TABLE: NULL
  ACTION_REFERENCE_OLD_ROW: OLD
  ACTION_REFERENCE_NEW_ROW: NEW
                   CREATED: 2018-08-08 10:10:12.61
                  SQL_MODE: ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,
                            NO_ZERO_IN_DATE,NO_ZERO_DATE,
                            ERROR_FOR_DIVISION_BY_ZERO,
                            NO_ENGINE_SUBSTITUTION
                   DEFINER: me@localhost
      CHARACTER_SET_CLIENT: utf8mb4
      COLLATION_CONNECTION: utf8mb4_0900_ai_ci
        DATABASE_COLLATION: utf8mb4_0900_ai_ci

Trigger information is also available from the SHOW TRIGGERS statement. See Section 15.7.7.40, “SHOW TRIGGERS Statement”.