Creating package specifications (PL/SQL)

A package specification establishes which package objects can be referenced from outside of the package. Objects that can be referenced from outside of a package are called the public elements of that package.

The following example shows how to create a package specification named EMP_ADMIN, consisting of two functions and two stored procedures.

CREATE OR REPLACE PACKAGE emp_admin
IS

   FUNCTION get_dept_name (
      p_deptno        NUMBER DEFAULT 10
   )
   RETURN VARCHAR2;
   FUNCTION update_emp_sal (
      p_empno         NUMBER,
      p_raise         NUMBER
   )
   RETURN NUMBER;
   PROCEDURE hire_emp (
      p_empno         NUMBER,
      p_ename         VARCHAR2,
      p_job           VARCHAR2,
      p_sal           NUMBER,
      p_hiredate      DATE DEFAULT sysdate,
      p_comm          NUMBER DEFAULT 0,
      p_mgr           NUMBER,
      p_deptno        NUMBER DEFAULT 10
   );
   PROCEDURE fire_emp (
      p_empno         NUMBER
   );

END emp_admin;

Attention:

When you use CREATE or REPLACE syntax for package specification of package whose body was created by a CREATE PACKAGE BODY statement, the existing package body is dropped and needs to be re-created before any of package objects are invoked.