Question

我有一个员工，司机和机械表。驱动程序不能是机制，反之亦然，我需要创建一个过程VERIFY来验证此语句。目前我有这个。

CREATE OR REPLACE PROCEDURE VERIFY IS
ENAME VARCHAR(25);
MESSAGE VARCHAR(50) := 'OK';
CHECK1 BOOLEAN := FALSE;

DRIVERNUM TRKEMPLOYEE.E#%TYPE;
MECHANICNUM TRKEMPLOYEE.E#%TYPE;

CURSOR DRIVERNUM_CURSOR IS SELECT E# FROM TRKDRIVER;
CURSOR MECHANICNUM_CURSOR IS SELECT E# FROM TRKMECHANIC;

BEGIN
OPEN DRIVERNUM_CURSOR;
LOOP
FETCH DRIVERNUM_CURSOR INTO DRIVERNUM;

    OPEN MECHANICNUM_CURSOR;
    LOOP
    FETCH MECHANICNUM_CURSOR INTO MECHANICNUM;

        IF MECHANICNUM_CURSOR%NOTFOUND THEN
        EXIT;
        END IF;

        IF (DRIVERNUM = MECHANICNUM) THEN 
        SELECT NAME INTO ENAME FROM TRKEMPLOYEE WHERE E# = DRIVERNUM;
        DBMS_OUTPUT.PUT_LINE('EMPLOYEE#: ' || TO_CHAR(DRIVERNUM));
        DBMS_OUTPUT.PUT_LINE('EMPLOYEENAME: ' || ENAME);
        CHECK1 := TRUE;
        END IF;

    END LOOP;
    CLOSE MECHANICNUM_CURSOR;

    IF DRIVERNUM_CURSOR%NOTFOUND THEN
    EXIT;
    END IF;

END LOOP;
CLOSE DRIVERNUM_CURSOR;


IF CHECK1 = FALSE THEN
DBMS_OUTPUT.PUT_LINE(MESSAGE);
END IF;



EXCEPTION
    WHEN OTHERS THEN
        DBMS_OUTPUT.PUT_LINE('NULL');

END;
/


EXECUTE VERIFY;

它警告我说用编译错误创建的过程。请帮忙谢谢！而且在我的代码中说明，如果没有也被注册为机械师的驱动程序，我需要它向我显示一条消息“OK”。

Answer 1

您的代码过于复杂。要找出那些同时是机制和驱动程序的人，请循环查询：

SELECT d.E#, e.NAME
FROM TRKDRIVER d
JOIN TRKMECHANUC m on m.E# = d.E#
JOIN TRKEMOYEE e on e.E# = d.E#

结果与许多循环，测试和查询产生的结果相同。

创建过程以验证驱动程序是否为机械师

1 个答案: