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我有一张 EMP 表,我想创建一个触发器来“在雇用新下属时以员工的工资增加 100 个单位。

  CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
    ENAME VARCHAR2(10),
    JOB VARCHAR2(9),
    MGR NUMBER(4),
    HIREDATE DATE,
    SAL NUMBER(7, 2),
    COMM NUMBER(7, 2),
    DEPTNO NUMBER(2));

    INSERT INTO EMP VALUES (7499, 'ALLEN', 'SALESMAN', 7698, TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600, 300, 30);
    INSERT INTO EMP VALUES (7369, 'SMITH', 'CLERK',    7902, TO_DATE('17-DEC-1980', 'DD-MON-YYYY'), 800, NULL, 20);
    INSERT INTO EMP VALUES (7521, 'WARD',  'SALESMAN', 7698, TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30);
    INSERT INTO EMP VALUES(7566, 'JONES', 'MANAGER',  7839, TO_DATE('2-APR-1981',  'DD-MON-YYYY'), 2975, NULL, 20);
    INSERT INTO EMP VALUES (7654, 'MARTIN', 'SALESMAN', 7698,TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);
    INSERT INTO EMP VALUES (7698, 'BLAKE', 'MANAGER', 7839,TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30);
    INSERT INTO EMP VALUES (7782, 'CLARK', 'MANAGER', 7839,TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10);
    INSERT INTO EMP VALUES (7788, 'SCOTT', 'ANALYST', 7566,TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
    INSERT INTO EMP VALUES (7839, 'KING', 'PRESIDENT', NULL,TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);
    INSERT INTO EMP VALUES (7844, 'TURNER', 'SALESMAN', 7698,TO_DATE('8-SEP-1981', 'DD-MON-YYYY'), 1500, 0, 30);
    INSERT INTO EMP VALUES (7876, 'ADAMS', 'CLERK', 7788,TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);
    INSERT INTO EMP VALUES (7900, 'JAMES', 'CLERK', 7698,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 950, NULL, 30);
    INSERT INTO EMP VALUES (7902, 'FORD', 'ANALYST', 7566,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 3000, NULL, 20);
    INSERT INTO EMP VALUES (7934, 'MILLER', 'CLERK', 7782,TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);

我的触发器是:

CREATE TRIGGER salary_increase
  AFTER UPDATE OF sal ON emp
  FOR EACH ROW

BEGIN
  UPDATE emp SET sal = sal + 100.0
        WHERE sal='800';
END salary_increse;
/

结果:(Trigger created.我的问题-->工资没涨)

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1 回答 1

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您的触发器声明为FOR EACH ROW,这是正确的;但这意味着您不需要运行 UPDATE 来更改列的值,您可以直接更改它,例如:

CREATE TRIGGER salary_increase
  AFTER UPDATE OF sal ON emp
  FOR EACH ROW

BEGIN
  IF :NEW.sal = 800.0 THEN
    :NEW.sal = :NEW.sal + 100.0;
  END IF;
END salary_increse;
/

这只是一个示例 - 它使用了您自己的触发器所隐含的逻辑,但它没有实现您的分配所描述的逻辑(“在雇用新下属时以员工的工资增加 100 个单位。”)。我把它留给你作为练习。

于 2012-12-20T04:39:54.097 回答