Question

我有一个插入查询进入链接到QuickBooks的一个表。表Test_InvoiceLine具有很多完全相同的Part_ID和Descriptions。

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?>

如何编写查询进入InvoiceLine表并删除具有相同Part_ID和Description的重复项？

Answer 1

这是SQL Server，但是ROW_NUMBER被其他RDMS广泛使用。

这是您需要的查询。

;WITH Data AS

(
    SELECT 
        Part_ID,Description,
        RowNumber = ROW_NUMBER() OVER(PARTITION BY  Part_Id,Description ORDER BY Part_Id,Description)
    FROM  Test_InvoiceLine
)
DELETE FROM Data WHERE RowNumber > 1

根据您的帖子，我不知道More_Info在这里有什么不同，因为重复键不包含它，但是，如果您需要检查delete语句中的more_info值，那么也许可以使用类似的方法转到下面的查询。

;WITH Data AS
(
    SELECT  
        More_Info,
        Part_ID,Description,
        RowNumber = ROW_NUMBER() OVER(PARTITION BY  Part_Id,Description ORDER BY Part_Id,Description)
    FROM  Test_InvoiceLine    
)

DELETE T
FROM Test_InvoiceLine T
INNER JOIN Data D ON D.RowNumber > 1 AND D.MoreInfo = "Y" AND D.Part_Id = T.Part_ID

Answer 2

使用CTE作为临时结果集。本质上，您将查询按条件划分的重复记录，然后删除不是第一条记录的记录（保留原始记录）。

在吹走任何东西之前，请仔细检查我，因为距离我这样做已经有一段时间了，但这应该可以工作。

  WITH CTE AS(
       SELECT Part_ID, Description,
           RowNum = ROW_NUMBER()OVER(PARTITION BY Part_ID, Description ORDER BY Part_ID, Description)
       FROM Test_InvoiceLine
    )
    DELETE FROM CTE WHERE RowNum > 1

来源：How to delete duplicate records in SQL Server

Answer 3

是否有理由需要插入然后删除？如果您要插入->删除，听起来好像您实际上是在尝试通过Part_ID更新数据。

update  InvoiceLine a

set     More_Info = b.Description       

from (  select  Part_ID,
                Description
        from    Test_InvoiceLine    ) b

where   b.Part_ID = a.Part_ID

这将用More_Info更新InvoiceLine表中的Description。

如何创建删除查询以删除具有条件的行？

3 个答案: