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["Table閃亮登場"]

主表:Base(BaseID Int,BaseName Nvarchar(200))

關系表:BaseForUser(BaseForUserID Int,BaseID Int)

["一些描述“]

要刪除BaseID為1數據,當然BaseForUser中BaseID為1的數據也要刪除...
(並且要刪除的數據還不多,Base表一條數據,BaseForUser表中10條數據左右)
But  BaseForUser中數據比較多(客戶比較多，你懂得),一億多...

["第一個版本"]

Declare @BaseID Int = 1
Delete From BaseForUser Where
 
 BaseID = @BaseID

Delete From Base Where BaseID = @BaseID

--耗時 1分鐘多...Pass

["第2個版本"]

第二個版本:
Delete Base From (Select BaseID From BaseForUser Where BaseID = @BaseID) U Where Base.BaseID = U.BaseID

--耗時50s...Pass

["第③個版本"]

--確定範圍
Declare @User Table(BaseForUserID Int Primary Key)
Insert Into
 
 @User 
Select T.ClassTableGenerateForStudentID 
From BaseForUser U With(NoLock)
Where U.BaseID = @BaseID

Delete From BaseForUser
Where BaseForUserID Between ( Select Min(BaseForUserID) From @User ) 
And ( Select Max(BaseForUserID) From @User ) And BaseID = @BaseID

--耗時10s，好吧，先這樣吧...-_-||

x

MSSQL 記一次刪除數據特別慢