Rule Dialog v9
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.
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 theBrowser
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.
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 beSelect
,Insert
,Update
, orDelete
. - Move the
Do Instead
switch toYes
indicate that the commands should be executed instead of the original command; if Do Instead specifiesNo
, the rule will be invoked in addition to the original command.
Click the Condition
tab to continue.
Specify a SQL conditional expression that returns a boolean value in the editor.
Click the Commands
tab to continue.
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:
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 theTabbed 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.