批量更新不结束，剩余数据不更新

Question

我需要批量更新一个table，但是没有用。我尝试了以下 2 个选项。

这两个选项都会更新前 10 行，但更新仍然是运行。但只有 10 行保持更新。

似乎更新从未完成，计数显示 table 中要更新的记录多于记录数。

请指教。

-- 选项#1

SET NOCOUNT OFF

IF OBJECT_ID('tempdb..#Table') IS NOT NULL
BEGIN 
    DROP TABLE #Table   
END

-- select count(*) from  #Table where ID = 0
-- select * from #Table

CREATE TABLE #Table ( ID INT )

WHILE (1 = 1)
    AND ( Select count(*) from #Table ) < 10000
BEGIN
    BEGIN TRANSACTION

    INSERT INTO #Table (ID) 
    VALUES (1)

    IF @@ROWCOUNT = 10000 -- terminating condition;
    BEGIN

    COMMIT TRANSACTION

    BREAK

    END
END

-- UPDATE
WHILE (1 = 1)
BEGIN
    BEGIN TRANSACTION

    UPDATE TOP (10) upd
        SET ID = 0
    FROM #Table upd

    IF @@ROWCOUNT = 0 -- terminating condition;
    BEGIN

    COMMIT TRANSACTION

    BREAK

    END
END

-- 选项#2

SET NOCOUNT OFF

IF OBJECT_ID('tempdb..#Table2') IS NOT NULL
BEGIN 
    DROP TABLE #Table2  
END

-- select count(*) from  #Table2 where ID = 0
-- select * from  #Table2

CREATE TABLE #Table2 ( ID INT )

--DECLARE @rows INT
--DECLARE @count INT

WHILE (1 = 1)
    AND ( Select count(*) from #Table2 ) < 10000
BEGIN
    BEGIN TRANSACTION

    INSERT INTO #Table2 (ID) 
    VALUES (1)

    IF @@ROWCOUNT = 10000 -- terminating condition;
    BEGIN

    COMMIT TRANSACTION

    BREAK

    END
END

DECLARE @rows INT
DECLARE @count INT

-- UPDATE
SET @rows = 1
SET @count = 0

WHILE @rows > 0
BEGIN
    BEGIN TRANSACTION

    UPDATE TOP (10) #Table2 -- upd
        SET ID = 0
    --  FROM #Table upd

    SET @rows = @@ROWCOUNT
    SET @count = @count + @rows

    RAISERROR('COUNT %d', 0, 1, @count) WITH NOWAIT

    COMMIT TRANSACTION
END

Answer 1

好的，您的代码有几个问题。

您不能在更新中使用 TOP - 但是它相当直接地使用子查询限制行，如图所示。
您将所有 ID 设置为 1 因此无法唯一标识一行，您只能更新所有 ID。我假设在你的现实生活中你会有唯一的 ID，我已经修改了代码以适应。
我不确定各种嵌套交易的意图，它们似乎完成不了多少，也不符合逻辑。

    IF OBJECT_ID('tempdb..#Table2') IS NOT NULL
    BEGIN 
        DROP TABLE #Table2;
    END

    CREATE TABLE #Table2 (ID INT);

    DECLARE @Count int = 0;

    WHILE (select count(*) from #Table2) < 10000 BEGIN
        INSERT INTO #Table2 (ID) 
        VALUES (@Count)

        -- Make sure we have a unique id for the test, else we can't identify 10 records
        set @Count = @Count + 1;
    END

    -- While exists an 'un-updated' record continue
    WHILE exists (select 1 from #Table2 where ID > 0) BEGIN
        -- Update any top 10 'un-updated' records
        UPDATE #Table2 SET
          ID = 0
        where id in (select top 10 id from #Table2 where ID > 0)
    END

    DROP TABLE #Table2

批量更新不结束，剩余数据不更新

UPDATE in Batches Does Not End and Remaining Data Does Not Get Updated

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