3

MERGE一連のレコードをテーブルに入れる必要があります。ソース内のUpdateType列は、ソースにないDELETE行をターゲットに含めるかどうかを決定します。

UpdateType等しいDか... RD=Delta、R=Refresh

の場合D、DELETEターゲットから一致しない
場合Rは、ターゲットから一致しない場合DELETE。

WHILEプロセスがどのように機能するかをよりよく模倣するために、単一のテーブルを反復処理する があります。

MERGEでこれを達成できますか? または、他にどのようなオプションがありますか?

SQL フィドル: http://www.sqlfiddle.com/#!3/9cdfe/16

これが私の例です。唯一の問題は...WHEN NOT MATCHED BY SOURCE節でソース値を使用できないことです。

DECLARE @BaseTable TABLE
(   RN int  
    ,Store int
    ,UpdateType char(1)
    ,ItemNumber int
    ,Name varchar(50)
)

INSERT INTO @BaseTable
SELECT *
FROM
(
    SELECT 1 RN, 1 Store, 'D' UpdateType, 1 ItemNumber, 'Wheel' Name
    UNION ALL
    SELECT 2, 1, 'D', 1, 'Big Wheel'
    UNION ALL
    SELECT 3, 1, 'D', 2, 'Light'
    UNION ALL
    SELECT 4, 1, 'R', 1, 'Wide Wheel'
    UNION ALL
    SELECT 5, 1, 'D', 1, 'Small Wheel'
    UNION ALL
    SELECT 5, 1, 'D', 4, 'Trunk'
)B

SELECT bt.* FROM @BaseTable bt

DECLARE @Tab TABLE
(   Store int
    ,UpdateType char(1)
    ,ItemNumber int
    ,Name varchar(50)
)

DECLARE @count int = 1
--Loop over each row to mimic how the merge will be called.
WHILE @count <= 5
BEGIN  
    MERGE INTO @Tab T
    USING
    (
        SELECT bt.RN,
                bt.Store,
                bt.UpdateType,
                bt.ItemNumber,
                bt.Name,
                tab.Store IsRefresh
        FROM @BaseTable bt
        LEFT JOIN
        (   --If ANY previous ITERATION was a 'R' then, all subsequent UpdateType MUST = 'R'
            --I'm hoping there is a better way to accomplish this.
            SELECT Store
            FROM @Tab
            WHERE UpdateType = 'R'
            GROUP BY Store
            HAVING COUNT(Store) > 1
        )tab
            ON bt.Store = tab.Store
        WHERE bt.RN = @count
    )S
        ON S.Store = T.Store AND S.ItemNumber = T.ItemNumber
    WHEN MATCHED THEN
        UPDATE
        SET T.UpdateType = CASE WHEN S.IsRefresh IS NOT NULL THEN 'R' ELSE S.UpdateType END,
        T.Name = S.Name
    WHEN NOT MATCHED BY TARGET THEN
        INSERT(Store,UpdateType,ItemNumber,Name) VALUES(S.Store,S.UpdateType,S.ItemNumber,S.Name)
    --WHEN NOT MATCHED BY SOURCE AND S.UpdateType = 'R' THEN
    --  DELETE
        ;
    SET @count = @count + 1
END

SELECT * FROM @Tab

--@Tab Expected Result:
-- 1 'R' 1 'Small Wheel'
-- 1 'R' 4 'Trunk'
4

1 に答える 1

1

次のコードは、あなたが望むことをするように見えます:

CREATE TABLE #BaseTable
(   RN int  
    ,Store int
    ,UpdateType char(1)
    ,ItemNumber int
    ,Name varchar(50)
)

INSERT INTO #BaseTable
SELECT *
FROM
(
    SELECT 1 RN, 1 Store, 'D' UpdateType, 1 ItemNumber, 'Wheel' Name
    UNION ALL
    SELECT 2, 1, 'D', 1, 'Big Wheel'
    UNION ALL
    SELECT 3, 1, 'D', 2, 'Light'
    UNION ALL
    SELECT 4, 1, 'R', 1, 'Wide Wheel'
    UNION ALL
    SELECT 5, 1, 'D', 1, 'Small Wheel'
    UNION ALL
    SELECT 5, 1, 'D', 4, 'Trunk'
)B

CREATE TABLE #Tab
(   Store int
    ,UpdateType char(1)
    ,ItemNumber int
    ,Name varchar(50)
)
SELECT bt.* FROM #BaseTable bt  -- Output for debugging - delete in production. 

DECLARE @count int = 1
DECLARE @Input TABLE (Store int, UpdateType char(1), ItemNumber int, Name varchar(50))
--Loop over each row to mimick how the merge will be called.
WHILE @count <= 5
BEGIN
    DELETE FROM @Input
    INSERT INTO @Input SELECT Store, UpdateType, ItemNumber, Name  FROM #BaseTable WHERE RN = @Count

    SELECT * FROM @Input    -- Output for debugging - delete in production.

    -- Procedure Body
    DECLARE @Store int, @UpdateType char(1), @ItemNumber int, @Name varchar(50)
    DECLARE csrInput CURSOR FOR SELECT Store, UpdateType, ItemNumber, Name  FROM @Input
    OPEN csrInput
    WHILE 1=1
        BEGIN
            FETCH NEXT FROM csrInput INTO @Store, @UpdateType, @ItemNumber, @Name 
            IF @@FETCH_STATUS<>0 BREAK
            IF @UpdateType = 'D'
                MERGE INTO #Tab Dest
                USING (SELECT * FROM @Input WHERE Store = @Store AND ItemNumber = @ItemNumber) Src
                ON Dest.Store = Src.Store AND Dest.ItemNumber = Src.ItemNumber
                WHEN MATCHED THEN UPDATE SET Dest.UpdateType = Src.UpdateType, Dest.Name = Src.Name
                WHEN NOT MATCHED BY TARGET THEN INSERT (Store, UpdateType, ItemNumber, Name) VALUES (Src.Store, Src.UpdateType, Src.ItemNumber, Src.Name);
            ELSE    -- Assuming that @UpdateType can only be 'D' or 'R'...
                MERGE INTO #Tab Dest
                USING (SELECT * FROM @Input WHERE Store = @Store AND ItemNumber = @ItemNumber) Src
                ON Dest.Store = Src.Store AND Dest.ItemNumber = Src.ItemNumber
                WHEN MATCHED THEN UPDATE SET Dest.UpdateType = Src.UpdateType, Dest.Name = Src.Name
                WHEN NOT MATCHED BY TARGET THEN INSERT (Store, UpdateType, ItemNumber, Name) VALUES (Src.Store, Src.UpdateType, Src.ItemNumber, Src.Name)
                WHEN NOT MATCHED BY SOURCE THEN DELETE;

                SELECT * FROM #Tab  -- Output for debugging - delete in production. 

        END
    CLOSE csrInput
    DEALLOCATE csrInput
    -- End Procedure Body.

    SET @count += 1
END

最終出力:

Store UpdateType ItemNumber Name
1     D          1          Small Wheel
1     D          4          Trunk
于 2013-10-16T21:58:47.590 に答える