Question

我正在使用以下查询。我正在从一张桌子到另一张桌子移动1000行。但是，它只是传输交替的1000行，就是这样。

如果删除cte子句，我会获得完整数据。你能告诉我哪里错了吗？

DECLARE @BatchSize INT = 1000
DECLARE @Counter INT = 0
DECLARE @TableCount INT = 0
set @TableCount = (select count(*) from TableSource)
print @TableCount/@BatchSize //10000/1000

while @Counter < (@TableCount/@BatchSize+1)
BEGIN

    INSERT INTO TableDest   
    SELECT *    
    FROM TableSource MH
    inner join Table1 M
    on MH.Mid = M.Mid   
    order by HID OFFSET (@BatchSize * @Counter)ROWS FETCH NEXT @Batchsize ROWS ONLY;


    with cte as
    (
    SELECT HID
    FROM TableSource MH
    inner join Table1 M
    on MH.Mid = M.Mid   
    order by message_history_id OFFSET (@BatchSize * @Counter)ROWS FETCH NEXT @Batchsize ROWS ONLY
    )
    delete from TableSource where HID IN (select cte.HID from cte)

SET @Counter=@Counter+1;
END

为什么只插入1000行？

It only transfers following rows if the total rows are 10,000:
0-1000
2001-3000
4001-5000
6001-7000
8001-9000

我有大量数据，所以我这样做。我不想锁定整个表格，因此我无法选择或删除所有内容。

Answer 1

这是因为您在复制后从源表中删除了前1000行。下次再次应用1000偏移时。将cte子句移到循环外部并立即删除所有内容，你应该没问题。

编辑：其他选项是删除插入和放大的偏移量。删除语句并在循环中保留cte子句。

Answer 2

从选择中删除计数器

DECLARE @BatchSize INT = 1000
DECLARE @Counter INT = 0
DECLARE @TableCount INT = 0
set @TableCount = (select count(*) from TableSource)
print @TableCount/@BatchSize //10000/1000

while @Counter < (@TableCount/@BatchSize+1)
BEGIN

    INSERT INTO TableDest   
    SELECT *    
    FROM TableSource MH
    inner join Table1 M
    on MH.Mid = M.Mid   
    order by HID OFFSET (0/* REMOVED@BatchSize  * @Counter */)ROWS FETCH NEXT @Batchsize ROWS ONLY;


    with cte as
    (
    SELECT HID
    FROM TableSource MH
    inner join Table1 M
    on MH.Mid = M.Mid   
    order by message_history_id OFFSET (0/* REMOVED@BatchSize  * @Counter*/)ROWS FETCH NEXT @Batchsize ROWS ONLY
    )
    delete from TableSource where HID IN (select cte.HID from cte)
SET @Counter=@Counter+1;
END

Sql查询仅传输交替的行

2 个答案: