CREATE PROCEDURE Statement

The CREATE PROCEDURE statement creates or replaces a standalone stored procedure or a call specification.

A standalone stored procedure is a procedure (a subprogram that performs a specific action) that is stored in the database.

A call specification declares a Java method or a third-generation language (3GL) subprogram so that it can be called from PL/SQL. You can also use the SQL CALL statement to call such a method or subprogram. The call specification tells the database which Java method, or which named procedure in which shared library, to invoke when a call is made. It also tells the database what type conversions to make for the arguments and return value.

Topics:

• Prerequisites

• Syntax

• Semantics

• Examples

• Related Topics

Prerequisites

To create or replace a standalone stored procedure in your own schema, you must have the CREATE PROCEDURE system privilege. To create or replace a standalone stored procedure in another user's schema, you must have the CREATE ANY PROCEDURE system privilege.

To invoke a call specification, you may need additional privileges, for example, the EXECUTE object privilege on the C library for a C call specification.

To embed a CREATE PROCEDURE statement inside an Oracle precompiler program, you must terminate the statement with the keyword END-EXEC followed by the embedded SQL statement terminator for the specific language.

Syntax

create_procedure ::=

See:

• body ::=

• declare_section ::=

• parameter_declaration ::=

invoker_rights_clause ::=

call_spec ::=

Java_declaration ::=

C_declaration ::=

Semantics

OR REPLACE

Re-creates the procedure if it exists, and recompiles it.

Users who were granted privileges on the procedure before it was redefined can still access the procedure without being regranted the privileges.

If any function-based indexes depend on the procedure, then the database marks the indexes DISABLED.

schema

The name of the schema containing the procedure. The default is your own schema.

procedure_name

The name of the procedure to be created.

invoker_rights_clause

Specifies the AUTHID property of the procedure. For information about the AUTHID property, see "Invoker's Rights and Definer's Rights (AUTHID Property)".

body

The required executable part of the procedure and, optionally, the exception-handling part of the procedure.

declare_section

The optional declarative part of the procedure. Declarations are local to the procedure, can be referenced in body, and cease to exist when the procedure completes execution.

call_spec

Maps a Java or C method name, parameter types, and return type to their SQL counterparts.

In the Java_declaration, string identifies the Java implementation of the method.

EXTERNAL

The EXTERNAL clause is an alternative way of declaring a C method. In most cases, Oracle recommends that you use the LANGUAGE C syntax. However, EXTERNAL is required if a default argument is used as a parameter or if a parameter uses a PL/SQL data type that must be mapped (for example, Boolean). EXTERNAL causes the PL/SQL layer to be loaded so that the parameters can be properly evaluated.

Examples

Creating a Procedure: Example This statement creates the procedure remove_emp in the schema hr.

CREATE PROCEDURE remove_emp (employee_id NUMBER) AS
   tot_emps NUMBER;
   BEGIN
      DELETE FROM employees
      WHERE employees.employee_id = remove_emp.employee_id;
   tot_emps := tot_emps - 1;
   END;
/

The remove_emp procedure removes a specified employee. When you call the procedure, you must specify the employee_id of the employee to be removed.

The procedure uses a DELETE statement to remove from the employees table the row of employee_id.

In this example, external procedure c_find_root expects a pointer as a parameter. Procedure find_root passes the parameter by reference using the BY REFERENCE phrase.

CREATE PROCEDURE find_root
   ( x IN REAL ) 
   IS LANGUAGE C
      NAME c_find_root
      LIBRARY c_utils
      PARAMETERS ( x BY REFERENCE );

Related Topics

In this chapter:

• "ALTER PROCEDURE Statement"

• "CREATE FUNCTION Statement"

• "DROP PROCEDURE Statement"

In other chapters:

• "Parameter"

• "Procedure"

• Chapter 8, "PL/SQL Subprograms"