Trigger Templates (PDM)

PowerDesigner trigger templates and template items allow you to create triggers in a modular reusable fashion.

PowerDesigner uses pre-defined trigger templates to create triggers to implement referential integrity between tables. Trigger templates exist for each type of trigger supported by the DBMS. Each template specifies:

a Time – relevant to an event. One of:
- After
- Before
an Event – that can occur to a table row. One of:
- Delete
- Insert
- Update
Code – that performs the trigger action. The code may contain references to trigger template items, which are re-usable blocks of script.

You can create trigger templates and trigger template items in your DBMS definition file or in your model. These elements will be available as follows:

Trigger template or template item created in:	Available to
DBMS (shared definition file)	All models sharing the DBMS
DBMS (copied definition file	Current model only
Model	Current model only

For more information on the DBMS share and copied definition files, see Generating a Database from a PDM.

Note:

By modifying a DBMS template item, you modify the template item definition in the current DBMS. You should only modify a DBMS that is a copy of the DBMS shipped with PowerDesigner.

For more information on working with DBMS resource files, see the DBMS Resource File Reference chapter of the Customizing and Extending PowerDesigner manual.

Creating a Trigger Template
You can create a new trigger template in your DBMS definition file or as part of your model. You can begin by copying an existing template or write one from scratch.two types of trigger templates:
PowerDesigner Pre-defined Trigger Templates
The pre-defined DBMS templates provided with PowerDesigner control referential integrity constraints for insert, update, and delete events. Depending on the current DBMS, there is a before and after event template for each trigger type.
Modifying a Trigger Template
You can modify both your templates and those that are provided with PowerDesigner.
Trigger Template Properties
You can modify a trigger templates properties from its property sheet. The following sections detail the property sheet tabs that contain the properties most commonly entered for trigger templates.

Parent topic: Building Triggers and Procedures