Question

如何将多行处理为更新触发器/如何修改我的实际触发器以获得当前行为？如果我只更新一行效果很好，但如果我在同一时间更新多行，我会收到错误：

Msg 512，Level 16，State 1，Procedure TriggerUpdateAdvert，Line 9
子查询返回的值超过1。当子查询遵循=，！=，＆lt;，＆lt; =，＆gt;，＆gt; =或子查询用作表达式时，不允许这样做。

这是我的触发器：

 ALTER TRIGGER dbo.TriggerUpdateAdvert
 ON dbo.Advert FOR UPDATE
 AS
    DECLARE @OldStatus INT;
    DECLARE @NewStatus INT;
    DECLARE @ID UNIQUEIDENTIFIER;

    SET @ID=(SELECT I.ID_Advert FROM INSERTED I);
    PRINT @ID
    SET @OldStatus=(SELECT D.Status FROM DELETED D WHERE D.ID_Advert=@ID);
    SET @NewStatus=(SELECT I.Status FROM INSERTED I WHERE I.ID_Advert=@ID);


    IF(@OldStatus!=@NewStatus)
    BEGIN
    print @OldStatus
    print @NewStatus
        IF(@NewStatus=1 or @NewStatus=3)
        BEGIN
            UPDATE Advert SET Published_Date=GETDATE() WHERE ID_Advert=@ID
        END
    END


 GO

编辑：

我创建了下一个代码：

        UPDATE A
        SET A.Published_Date=GETDATE()
        FROM Advert A
        INNER JOIN Inserted I ON A.ID_Advert=I.ID_Advert
        INNER JOIN Deleted D ON D.ID_Advert=A.ID_Advert
        WHERE I.Status!=D.Status  AND (I.Status IN (1,3) AND D.Status NOT IN (1,3))

你有什么想法吗？

Answer 1

避免在触发器中使用PRINT。

并按照以下方式定义：

 ALTER TRIGGER dbo.TriggerUpdateAdvert
 ON dbo.Advert FOR UPDATE
 AS
   UPDATE Advert SET Published_Date=GETDATE() 
   WHERE ID_Advert IN (
     SELECT i.id 
     FROM inserted i 
     INNER JOIN deleted d 
     ON i.ID_Advert = d.ID_Advert
     WHERE i.Status <> d.Status
     AND i.Status IN (1,3)
   )
 END

Answer 2

UPDATE a SET Published_Date = CURRENT_TIMESTAMP
  FROM dbo.Advert AS a
  INNER JOIN inserted AS i ON a.ID_Advert = i.ID_Advert
  INNER JOIN deleted AS d  ON i.ID_Advert = d.ID_Advert
  WHERE i.Status IN (1,3) AND d.Status <> i.Status;

在sql触发器更新中处理多行

2 个答案: