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, DB_DATADIR, DELETE TRIGGER, DROP TABLE, GETENV(), INSERT, SELECT, SET AUTOCATALOG, SET TCACHE, 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. Databases in Recital are implemented as directories containing files that correspond to the tables and associated files in the database. Operating System file protection can be applied individually to the files for added security. The directory is a sub-directory of the Recital data directory. The environment variable / symbol DB_DATADIR points to the current Recital data directory and can be queried using the GETENV() function. Files from other directories can be added to the database using the ADD TABLE command or via the database catalog and SET AUTOCATALOG functionality. The '!' character must be included between the database name and the table name.
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)

Products

Recital Server, Recital