.. _procedure_dialog:

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The Procedure Dialog
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Use the *Procedure* dialog to create a procedure; procedures are supported by EDB Postgres Advanced Server. The *Procedure* dialog allows you to implement options of the CREATE PROCEDURE command; for more information about the CREATE PROCEDURE SQL command, please see the Database Compatibility for Oracle Developer's, available at:

     http://www.enterprisedb.com  

The *Procedure* dialog organizes the development of a procedure through the following dialog tabs: *General*, *Definition*, *Options*, *Arguments*, *Parameters*, and *Security*. The *SQL* tab displays the SQL code generated by dialog selections. 
 
.. image:: images/procedure_general.png

Use the fields in the *General* tab to identify a procedure:

* Use the *Name* field to add a descriptive name for the procedure. The name will be displayed in the *pgAdmin* tree control.
* Use the drop-down listbox next to *Owner* to select a role.
* Select the name of the schema in which the procedure will reside from the drop-down listbox in the *Schema* field.
* Store notes about the procedure in the *Comment* field.

Click the *Definition* tab to continue.

.. image:: images/procedure_definition.png

Use the fields in the *Definition* tab to define the procedure:

* Use the drop-down listbox next to *Language* to select a language. The default is *edbspl*. 
* Use the *Code* field to specify the code that will execute when the procedure is called.

Click the *Options* tab to continue.

.. image:: images/procedure_options.png

Use the fields in the *Options* tab to describe or modify the behavior of the procedure:

* Use the drop-down listbox under *Volatility* to select one of the following. *VOLATILE* is the default value.

    * *VOLATILE* indicates that the value can change even within a single table scan, so no optimizations can be made. 
    * *STABLE* indicates that the procedure cannot modify the database, and that within a single table scan it will consistently return the same result for the same argument values, but that its result could change across SQL statements. 
    * *IMMUTABLE* indicates that the procedure cannot modify the database and always returns the same result when given the same argument values.

* Move the *Strict?* switch to indicate if the procedure always returns NULL whenever any of its arguments are NULL. If *Yes*, the procedure is not executed when there are NULL arguments; instead a NULL result is assumed automatically. The default is *No*.
* Move the *Security of definer?* switch to specify that the procedure is to be executed with the privileges of the user that created it. The default is *No*.
* Use the *Estimated cost* field to specify a positive number representing the estimated execution cost for the procedure, in units of cpu_operator_cost. If the procedure returns a set, this is the cost per returned row. 
* Move the *Leak proof?* switch to indicate whether the procedure has side effects — it reveals no information about its arguments other than by its return value. The default is *No*.   

Click the *Arguments* tab to continue.

.. image:: images/procedure_arguments.png

Use the fields in the *Arguments* tab to define an argument. Click *Add* to set parameters and values for the argument:

* Use the drop-down listbox next to *Data type* to select a data type.
* Use the drop-down listbox next to *Mode* to select a mode. Select *IN* for an input parameter; select *OUT* for an output parameter; select *INOUT* for both an input and an output parameter; or, select *VARIADIC* to specify a VARIADIC parameter.
* Write a name for the argument in the *Argument Name* field.
* Specify a default value for the argument in the *Default Value* field.

Click *Add* to define another argument; to discard an argument, click the trash icon to the left of the row and confirm deletion in the *Delete Row* popup.

Click the *Parameters* tab to continue.

.. image:: images/procedure_parameters.png

Use the fields in the *Parameters* tab to specify settings that will be applied when the procedure is invoked:

* Use the drop-down listbox next to *Parameter Name* in the *Parameters* panel to select a parameter. 
* Click the *Add* button to add the variable to *Name* field in the table.
* Use the *Value* field to specify the value that will be associated with the selected variable. This field is context-sensitive.

Click the *Security* tab to continue.

.. image:: images/procedure_security.png

Use the *Security* tab to assign privileges and define security labels.  

Use the *Privileges* panel to assign execute privileges for the procedure to a role:  

* Select the name of the role from the drop-down listbox in the *Grantee* field.
* Click inside the *Privileges* field. Check the boxes to the left of one or more privileges to grant the selected privilege to the specified user.
* Select the name of the role from the drop-down listbox in the *Grantor* field. The default grantor is the owner of the database.

Click *Add* to assign additional privileges; to discard a privilege, click the trash icon to the left of the row and confirm deletion in the *Delete Row* popup.

Use the *Security Labels* panel to define security labels applied to the procedure. Click *Add* to add each security label selection: 

* Specify a security label provider in the *Provider* field. The named provider must be loaded and must consent to the proposed labeling operation.
* Specify a a security label in the *Security Label* field. The meaning of a given label is at the discretion of the label provider. PostgreSQL places no restrictions on whether or how a label provider must interpret security labels; it merely provides a mechanism for storing them. 

Click *Add* to assign additional security labels; to discard a security label, click the trash icon to the left of the row and confirm deletion in the *Delete Row* popup.

Click the *SQL* tab to continue.

Your entries in the *Procedure* 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 selections made in the *Procedure* dialog: 

.. image:: images/procedure_sql.png

The example demonstrates creating a procedure that returns a list of employees from a table named *emp*.  The procedure is a SECURITY DEFINER, and will execute with the privileges of the role that defined the procedure.  
 
* 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.