NexusDB

Define a trigger.

Syntax

Usage

The CREATE TRIGGER statement creates a trigger that is stored in the database and associated with the subject table identified by table-name.

Notes

Examples

       CREATE TRIGGER orders_after_delete

       AFTER DELETE ON orders

       WHEN ( DELETING )

       DELETE FROM order_details WHERE orderID = OLD.orderID;

       CREATE TRIGGER enrolls_changes

       AFTER INSERT, DELETE, UPDATE ON enrolls

       REFERENCING OLD AS o NEW AS n

       BEGIN

IF INSERTING THEN

INSERT INTO enrolls_log ( action, n1, n2, n3, n4, stamp )

VALUES ( 'Insert', n.courseID, n.sectionID, n.studentID, n.grade, CURRENT_TIMESTAMP );

ELSEIF UPDATING THEN

INSERT INTO enrolls_log ( action, o1, n1, o2, n2, o3, n3, o4, n4, stamp )

VALUES ('Update', o.courseID, n.courseID, o.sectionID, n.sectionID,

o.studentID, n.studentID, o.grade, n.grade, CURRENT_TIMESTAMP );

ELSEIF DELETING THEN

INSERT INTO enrolls_log ( action, o1, o2, o3, o4, stamp )

VALUES ( 'Delete', o.courseID, o.sectionID, o.studentID, o.grade, CURRENT_TIMESTAMP );

END IF;

       END

Conformance