Create or replace role?

Question

How do you create or replace a role (that might or might not exist) in Oracle? For example, the following does not work:

CREATE OR REPLACE ROLE role_name;
  GRANT SELECT ON SCM1_VIEW_OBJECT_VW TO role_name;

Any way to do this without PL/SQL?

Answer 1

Solution

A combination of the given answers and a pragma control accomplishes this task for Oracle 10g.

CREATE OR REPLACE PROCEDURE create_role( role_name IN VARCHAR2 ) IS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
  EXECUTE IMMEDIATE 'CREATE ROLE '||role_name;
EXCEPTION
  WHEN OTHERS THEN
    -- ORA-01921: If The role name exists, ignore the error.
    IF SQLCODE <> -01921 THEN
      RAISE;
    END IF;
END create_role;

Test

This sequence works:

DROP ROLE role_name;
CREATE ROLE role_name;
CALL create_role( 'role_name' );
CALL create_role( 'role_name' );

The final create role statement fails, as expected:

DROP ROLE role_name;
CALL create_role( 'role_name' );
CREATE ROLE role_name;