SQL Server：如果不存在则触发更新

Question

我有以下触发因素使我感到悲伤。

ALTER TRIGGER [dbo].[T_DMS_Factory_I]
   ON  [dbo].[jobrun]
   AFTER INSERT
AS 
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for trigger here
    IF NOT EXISTS (select * from inserted i
                   inner join [db2].[dbo].[table2] t2 on t2.JobRunID = i.jobrun_id)
       UPDATE [db2].[dbo].[table2]
       SET ProdDt = i.jobrun_proddt,
           CreateDt = GETDATE(),
           JobrunID = i.jobrun_id,
           Start = i.jobrun_time,
           End = i.jobrun_stachgtm,
           Status = i.jobrun_status,
           ActiveDuration = i.jobrun_duration,
           TotalDuration = i.jobrun_duration
       FROM inserted i
       INNER JOIN jobmst jm ON jm.jobmst_id = i.jobmst_id
       WHERE jm.jobmst_alias = 'blah'
END

上面的工作正常，但它使用我不需要的相同数据更新所有行。 我只希望它更新从另一列称为baseEnd的插入时间之前的时间所在的baseEnd

WHERE jm.jobmst_alias = 'blah' AND baseEnd <= i.jobrun_time AND JobRunID IS NOT NULL

我以为那是应该的，但事实并非如此。 我究竟做错了什么？

Answer 1

查看代码中的表

UPDATE [db2].[dbo].[table2]
SET 
....
FROM inserted i
inner join jobmst jm on jm.jobmst_id = i.jobmst_id
where jm.jobmst_alias = 'blah'

如果要更新匹配的记录，则FROM子句中不应该包含table2。

否则，您只是从插入表和Jobmst表中取回一些记录，并将其中之一的值激发到table2中的所有记录中

这就是为什么它不起作用

很难完全了解您要实现的逻辑，但这可能正是您所需要的

UPDATE t2
SET ProdDt = i.jobrun_proddt,
CreateDt = GETDATE(),
JobrunID = i.jobrun_id,
Start = i.jobrun_time,
End = i.jobrun_stachgtm,
Status = i.jobrun_status,
ActiveDuration = i.jobrun_duration,
TotalDuration = i.jobrun_duration
FROM inserted i
inner join jobmst jm on jm.jobmst_id = i.jobmst_id
inner join [db2].[dbo].[table2] t2 ON  t2.baseEnd <= i.jobrun_time 
where jm.jobmst_alias = 'blah'