SQL if update() 语句作为触发器

Question

我希望我的触发器仅在旧值不等于新值时才在更新时执行。如果值保持不变，我不希望我执行 if 块。

if UPDATE(interview)
    BEGIN 
    EXEC sp_send_dbmail
            @profile_name = 'SM_PRFL',
    @recipients = 'email',
    @subject = 'this is a test' ,
    @body = 'message'
            END

Answer 1

查看以下链接，查找"在 INSTEAD OF 触发器中使用插入和删除的表"：http://msdn.microsoft.com/en-us/library/ms191300（SQL.90）.aspx

这应该允许您根据需要执行测试并执行操作。 例如，您可以...

If ( Update(interview))
BEGIN
    -- If column esb has been changed from its previous value
    IF ((SELECT esb FROM INSERTED) <> select esb FROM DELETED)
    BEGIN
    EXEC sp_send_dbmail
            @profile_name = 'SM_PRFL',
    @recipients = 'email',
    @subject = 'this is a test' ,
    @body = 'message'
    END
END