Question

将数据库触发器写入

在表格
如果记录超过10
从周一至周六删除超过2个月的数据，日期不应该是该月的第1天。（即离开星期日和月份数据的第一个月大于2个月）

我试过这段代码，

CREATE OR REPLACE TRIGGER EMP_INFO_BFT BEFORE
  INSERT OR DELETE OR UPDATE ON EMP_INFO
  FOR EACH ROW 
  DECLARE l_TIME NUMBER(10);
  l_RECORD NUMBER;
  BEGIN
   l_TIME:=TO_CHAR(SYSDATE,'HH24');
    IF l_TIME NOT BETWEEN 18 AND 10 THEN
    RAISE_APPLICATION_ERROR(-20003,'TIME ALREADY OVER.....TRANSACTION NOT ALLOWED NOW');
   END IF;
    DELETE
    FROM EMP_INFO
    WHERE TRUNC (HIRE_DATE )                < ADD_MONTHS (TRUNC (SYSDATE), -2)
    AND TO_CHAR (TRUNC (HIRE_DATE ), 'DY') != 'SUN'
    AND TO_CHAR (TRUNC (HIRE_DATE ), 'DD') != '01';
    SELECT COUNT(*) INTO l_RECORD FROM EMP_INFO;
    IF l_RECORD>=10 THEN
      RAISE_APPLICATION_ERROR(-20005,'10 RECORD ALLOWED IN EMP_INFO TABLE');
    END IF;
  END;

插入时出现变异错误。

Answer 1

变异错误

Check this link基本上说：

＆＃34;如果触发器确实导致变异表错误，唯一真正的选择是将触发器重写为语句级触发器。

变异表错误仅影响行级触发器。＆＃34;

您的代码没有引用:NEW或:OLD，因此将其更改为语句级别触发器应该很简单，只需删除FOR EACH ROW。

<强> PS

我认为你的BETWEEN不会起作用。

更改

IF l_TIME NOT BETWEEN 18 AND 10 THEN

到

IF l_TIME BETWEEN 10 AND 18 THEN
    NULL;
ELSE

会解决它。

Answer 2

将此触发器设为自动触发器，请检查以下代码：

CREATE OR REPLACE TRIGGER EMP_INFO_BFT BEFORE
  INSERT OR DELETE OR UPDATE ON EMP_INFO
  FOR EACH ROW 
  DECLARE l_TIME NUMBER(10);
  l_RECORD NUMBER;
pragma autonomous_transaction;
  BEGIN
   l_TIME:=TO_CHAR(SYSDATE,'HH24');
    IF l_TIME NOT BETWEEN 18 AND 10 THEN
    RAISE_APPLICATION_ERROR(-20003,'TIME ALREADY OVER.....TRANSACTION NOT ALLOWED NOW');
   END IF;
    DELETE
    FROM EMP_INFO
    WHERE TRUNC (HIRE_DATE )                < ADD_MONTHS (TRUNC (SYSDATE), -2)
    AND TO_CHAR (TRUNC (HIRE_DATE ), 'DY') != 'SUN'
    AND TO_CHAR (TRUNC (HIRE_DATE ), 'DD') != '01';
    commit;
    SELECT COUNT(*) INTO l_RECORD FROM EMP_INFO;
    IF l_RECORD>=10 THEN
      RAISE_APPLICATION_ERROR(-20005,'10 RECORD ALLOWED IN EMP_INFO TABLE');
    END IF;
  END;

行级触发器中的变异表错误

2 个答案: