Information Schema TRIGGERED_UPDATE_COLUMNS

The Information Schema TRIGGERED_UPDATE_COLUMNS table identifies which columns are modified by the SET clause of a specific trigger.

This table is available from MariaDB 12.2.

The Information Schema TRIGGERED_UPDATE_COLUMNS table shows columns specified in triggers for update operations.

Columns are displayed only if the user has non-SELECT privileges on the columns.

It contains the following columns:

Column	Description
TRIGGER_CATALOG	Always def in MariaDB.
TRIGGER_SCHEMA	Name of the database containing the trigger.
TRIGGER_NAME	Name of the trigger.
EVENT_OBJECT_CATALOG	Always def in MariaDB
EVENT_OBJECT_SCHEMA	Name of the database containing the table that the trigger is defined on.
EVENT_OBJECT_TABLE	Name of the table that the trigger is defined on.
EVENT_OBJECT_COLUMN	Name of the column that the trigger is defined on.

Examples

CREATE TABLE t (a INT, b INT, c INT);
INSERT INTO t VALUES (1, 2, 3);
CREATE TABLE t1 (a_old INT, b_old INT, a_new INT, b_new INT);
CREATE TABLE t2 (a_old INT, b_old INT, a_new INT, b_new INT); 
CREATE TRIGGER trigger_before_update BEFORE UPDATE OF a, b ON t 
  FOR EACH ROW INSERT INTO t1 VALUES (OLD.a, OLD.b, NEW.a, NEW.b);

SELECT * FROM INFORMATION_SCHEMA.TRIGGERED_UPDATE_COLUMNS\G 
*************************** 1. row ***************************
 TRIGGER_CATALOG: def 
TRIGGER_SCHEMA: test 
TRIGGER_NAME: trigger_before_update 
EVENT_OBJECT_CATALOG: def 
EVENT_OBJECT_SCHEMA: test 
EVENT_OBJECT_TABLE: t 
EVENT_OBJECT_COLUMN: a 
*************************** 2. row *************************** 
TRIGGER_CATALOG: def 
TRIGGER_SCHEMA: test 
TRIGGER_NAME: trigger_before_update 
EVENT_OBJECT_CATALOG: def 
EVENT_OBJECT_SCHEMA: test 
EVENT_OBJECT_TABLE: t 
EVENT_OBJECT_COLUMN: b

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