华南农业大学数据库系统概念实验报告七

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END IF; END; UPDATE emp SET sal=800 WHERE empno=7876; UPDATE emp SET sal=450 WHERE empno=7876; COMMIT; SELECT empno,ename,job,sal FROM emp WHERE empno=7876; ^`

【练习3】限定对emp表的修改，只能修改部门10的雇员工资。 CREATE OR REPLACE TRIGGER CHECK_NO BEFORE UPDATE ON emp FOR EACH ROW BEGIN IF :new.DEPTNO<>10 THEN RAISE_APPLICATION_ERROR(-20001, '修改的部门不符,操作取消！'); END IF; END; ^`

UPDATE emp SET sal=8000 WHERE deptno=20; UPDATE emp SET sal=6789 WHERE deptno=30; UPDATE emp SET sal=888 WHERE deptno=10; select * from emp; ^`

【训练4】 CREATE TRIGGER CASCADE_UPDATE AFTER UPDATE OF deptno ON DEPT FOR EACH ROW BEGIN UPDATE EMP SET EMP.DEPTNO=:NEW.DEPTNO WHERE EMP.DEPTNO=:OLD.DEPTNO; END; ^`

UPDATE dept SET deptno=11 WHERE deptno=10; COMMIT; SELECT empno,ename,deptno FROM emp;