CREATE TRIGGER

Purpose

Creates a trigger for a table

Syntax

CREATE TRIGGER ON [<database>!]<table>

FOR UPDATE | INSERT | DELETE

AS <expression>

See Also

ADD TABLE, ALTER INDEX, ALTER TABLE, CONSTRAINTS, DATA TYPES, DELETE TRIGGER, DROP TABLE, GETENV(), INSERT, SELECT, SET AUTOCATALOG, SET XMLFORMAT,

Description

The CREATE TRIGGER command is used to create a trigger for the specified table. Triggers cause the logical <expression> to be evaluated when certain operations are attempted.

Trigger	Operation
UPDATE	Attempt to modify an existing record
INSERT	Attempt to add a new record
DELETE	Attempt to delete an existing record

If the <expression> evaluates to False (.F.) the operation does not complete. If the <expression> evaluates to True (.T.) the operations does complete.

Keywords	Description
database	The name of the database to which the table belongs.
table	The name of the table
INSERT | DELETE	Specifies the type of trigger to be created.
expression	A logical expression to be evaluated

Example

USE accounts
CREATE TRIGGER ON customer FOR UPDATE AS not empty(CustName)