下面示例演示了如何在包声明中定义常量，以及在包体的子程序中定义本地变量。前者作用范围是整个包，对调用者可见；后者作用范围是当前子程序内部，对调用者不可见。

示例：在子程序里声明变量和常量并赋值

delimiter /
CREATE OR REPLACE PACKAGE pkg_ware_mgmt as
    MAX_WARES           constant number(2,0) := 10;
    MAX_DISTS_PER_WARE  constant number(2,0) := 10;
    FUNCTION  f_check_ware_exists(p_name IN varchar2) RETURN BOOLEAN ;
END;
/
delimiter ;
delimiter /
CREATE OR REPLACE PACKAGE BODY pkg_ware_mgmt as
    FUNCTION f_check_ware_exists( p_name IN varchar2 ) RETURN BOOLEAN
    IS
        i_cnt   number := -1;
        b_ret   boolean := FALSE;
    BEGIN
        SELECT count(*) INTO i_cnt FROM ware WHERE w_name = p_name AND rownum < 2;
        b_ret := (i_cnt = 1);
        RETURN b_ret;
    EXCEPTION
        WHEN OTHERS THEN            
            RETURN FALSE;
    END;
END; 
/
obclient> delimiter ;
obclient>
obclient> SELECT pkg_ware_mgmt.f_check_ware_exists('W_NAME_1') col1 ,pkg_ware_mgmt.f_check_ware_exists('W_NAME_3') col2 FROM DUAL;
+------+------+
| COL1 | COL2 |
+------+------+
|    0 |    0 |
+------+------+
1 row in set (0.05 sec)