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77 lines
2.5 KiB
ReStructuredText
77 lines
2.5 KiB
ReStructuredText
.. _rule_dialog:
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********************
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`Rule Dialog`:index:
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********************
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Use the *Rule* dialog to define or modify a rule for a specified table or view.
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A PostgreSQL rule allows you to define an additional action that will be
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performed when a SELECT, INSERT, UPDATE, or DELETE is performed against a table.
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The *Rule* dialog organizes the development of a rule through the *General*,
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*Definition*, *Condition*, *Commands* tabs. The *SQL* tab displays the SQL code
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generated by dialog selections.
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.. image:: images/rule_general.png
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:alt: Rule dialog general tab
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:align: center
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Use the fields in the *General* tab to identify the rule:
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* Use the *Name* field to add a descriptive name for the rule. The name will be
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displayed in the *pgAdmin* tree control. Multiple rules on the same table are
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applied in alphabetical name order.
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* Store notes about the rule in the *Comment* field.
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Click the *Definition* tab to continue.
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.. image:: images/rule_definition.png
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:alt: Rule dialog definition tab
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:align: center
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Use the fields in the *Definition* tab to write parameters:
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* Click inside the *Event* field to select the type of event that will invoke
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the rule; event may be *Select*, *Insert*, *Update*, or *Delete*.
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* Move the *Do Instead* switch to *Yes* indicate that the commands should be
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executed instead of the original command; if Do Instead specifies *No*, the
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rule will be invoked in addition to the original command.
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Click the *Condition* tab to continue.
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.. image:: images/rule_condition.png
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:alt: Rule dialog condition tab
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:align: center
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Specify a SQL conditional expression that returns a boolean value in the editor.
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Click the *Commands* tab to continue.
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.. image:: images/rule_commands.png
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:alt: Rule dialog commands tab
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:align: center
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Provide a command in the editor that defines the action performed by the rule.
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Click the *SQL* tab to continue.
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Your entries in the *Rule* dialog generate a SQL command (see an example below).
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Use the *SQL* tab for review; revisit or switch tabs to make any changes to the
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SQL command.
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Example
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*******
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The following is an example of the sql command generated by user selections in
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the *Rule* dialog:
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.. image:: images/rule_sql.png
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:alt: Rule dialog sql tab
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:align: center
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The example sends a notification when an UPDATE executes against a table.
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* Click the *Info* button (i) to access online help.
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* Click the *Save* button to save work.
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* Click the *Cancel* button to exit without saving work.
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* Click the *Reset* button to restore configuration parameters. |