To reference the types, items and subprograms that are declared within a package specification, you must use the dot notation. For example:
package_name.type_name package_name.item_name package_name.subprogram_name
You can execute the following SQL statement to invoke a function from the emp_admin package specification.
SELECT emp_admin.get_dept_name(10) FROM DUAL;
This statement invokes the get_dept_name function that is declared within the package emp_admin, and passes the department number as an argument to the function. The function returns the name of the department. The returned value is ACCOUNTING, which corresponds to department number 10.