Question

我在登台表中有超过一百万行。每月登台表获取行，插入主表后，将删除暂存中的那些行。

还有另一个名为allchanges的表，它跟踪对主表所做的所有更新（比如month1-address change，month2- phone change，所以所有更改都有2条记录）而master只有一条更新记录。

我将MERGE用于when matched，when not matched by target和when not matched by source。

WITH  NewAndChanged
AS    (SELECT   TOP 2 stg.[EmpName],
                       stg.[EmpNumber],

       FROM     staging AS stg
       ORDER BY stg.[EmpNumber]
       EXCEPT
       SELECT   TOP 2 mas.[EmpName],
                       mas.[EmpNumber],

       FROM    [Master] AS mas
       ORDER BY mas.EmpNumber)
MERGE INTO [Master]
 AS Target
USING NewAndChanged AS Source ON Target.EmpNumber = Source.EmpNumber
WHEN MATCHED AND (COALESCE (Target.EmpName, '') <> COALESCE (Source.EmpName, '')
                  ) THEN UPDATE 
    SET Target.EmpName           = Source.EmpName,


WHEN NOT MATCHED BY TARGET THEN INSERT ([EmpName], [EmpNumber])

WHEN NOT MATCHED BY SOURCE AND Target.Active = 1 THEN UPDATE 
    SET Active = 0
    output $action as act;

由于我一次只选择2行，when not matched by source将第2次迭代中前2行的活动设置为零。我怎么能克服这个？

SQL Server MERGE：“当与源不匹配时”

0 个答案: