Rule Dialog

Use the Rule dialog to define or modify a rule for a specified table or view. A PostgreSQL rule allows you to define an additional action that will be performed when a SELECT, INSERT, UPDATE, or DELETE is performed against a table.

The Rule dialog organizes the development of a rule through the General, Definition, Condition, Commands tabs. The SQL tab displays the SQL code generated by dialog selections.

Rule dialog general tab

Create Rule dialog - General tab

Use the fields in the General tab to identify the rule:

  • Use the Name field to add a descriptive name for the rule. The name will be displayed in the Browser tree control. Multiple rules on the same table are applied in alphabetical name order.

  • Store notes about the rule in the Comment field.

Click the Definition tab to continue.

Rule dialog definition tab

Create Rule dialog - Definition tab

Use the fields in the Definition tab to write parameters:

  • Click inside the Event field to select the type of event that will invoke the rule; event may be Select, Insert, Update, or Delete.

  • Move the Do Instead switch to Yes indicate that the commands should be executed instead of the original command; if Do Instead specifies No, the rule will be invoked in addition to the original command.

Click the Condition tab to continue.

Rule dialog condition tab

Create Rule dialog - Condition tab

Specify a SQL conditional expression that returns a boolean value in the editor.

Click the Commands tab to continue.

Rule dialog commands tab

Create Rule dialog - Commands tab

Provide a command in the editor that defines the action performed by the rule.

Click the SQL tab to continue.

Your entries in the Rule dialog generate a SQL command (see an example below). Use the SQL tab for review; revisit or switch tabs to make any changes to the SQL command.

Example

The following is an example of the sql command generated by user selections in the Rule dialog:

Rule dialog sql tab

Create Rule dialog - SQL tab

The example sends a notification when an UPDATE executes against a table.

  • Click the Info button (i) to access online help. View context-sensitive help in the Tabbed browser, where a new tab displays the PostgreSQL core documentation.

  • Click the Save button to save work.

  • Click the Cancel button to exit without saving work.

  • Click the Reset button to restore configuration parameters.