SQL Server Merge - 将匹配的记录与另一个临时表进行匹配

Question

我有一个MERGE更新数据的查询.如果没有匹配,我将源记录插入到获取输出到临时表.

是否可以将匹配的记录输入临时表？基本上为了避免在进一步处理中重复数据,我需要有匹配记录的副本.

这是我的MERGE命令:

MERGE Product.ProductHeaderRepository AS t 
USING (SELECT GETDATE() as d, c1, c2, c3,
Name FROM Supplier.ProductHeaderImport
WHERE (BatchID = @BatchID) ) AS s
ON dbo.GetProductHeaderId(s.c1,S.c2,S.c3) <0
WHEN NOT MATCHED BY TARGET THEN
  INSERT (Name, c1,c2,c3) VALUES (Name, c2,c2,c3)
OUTPUT INSERTED.iD, s.c1, s.c2, s.c3 INTO @TmpTable;

Answer 1

您可以创建一个MATCHED不会更改任何内容的子句,只需更新变量,例如

DECLARE @T1 TABLE (A INT, B INT);
DECLARE @T2 TABLE (A INT, B INT);
DECLARE @T3 TABLE (Action VARCHAR(20), A INT, B INT);

INSERT @T1 VALUES (1, 1), (2, 2), (3, 3);
INSERT @T2 VALUES (1, 0), (2, NULL), (4, 0);

DECLARE @I INT; -- VARIABLE TO UPDATE

MERGE @T2 B
USING @T1 A
    ON A.A = B.A
WHEN MATCHED THEN 
    UPDATE SET @I = 1   -- DO NOTHING MEANINGFUL IN THE UPDATE;
WHEN NOT MATCHED BY TARGET THEN 
    INSERT (A, B) VALUES (A.A, A.B)
OUTPUT $action, ISNULL(inserted.A, deleted.A), ISNULL(inserted.B, deleted.B) INTO @T3;

SELECT  *
FROM    @T3;

将返回:

Action  A   B
INSERT  3   3
UPDATE  1   0
UPDATE  2   NULL

因此,如果您添加新列以@TmpTable存储操作,则可以使用以下方法获取匹配的行:

SELECT  *
FROM    @TmpTable
WHERE   Action = 'UPDATE';

你的新行使用:

SELECT  *
FROM    @TmpTable
WHERE   Action = 'INSERT';