SQL Server資料庫刪除資料集中重複資料執行個體講解_MsSql

SQL Server資料庫操作中，有時對於表中的結果集，滿足一定規則我們則認為是重複資料，而這些重複資料需要刪除。如何刪除呢？本文我們通過一個例子來加以說明。

例子如下：

如下只要companyName,invoiceNumber,customerNumber三者都相同，我們則認為是重複資料，下面的例子示範了如何刪除。

declare @InvoiceListMaster table ( ID int identity primary key ,   companyName Nchar(20),   invoiceNumber int,   CustomerNumber int,   rmaNumber int )   insert  @InvoiceListMaster   select N'華為', 1001,100,200   union all   select N'華為', 1001,100,300   union all   select N'華為', 1001,100,301   union all   select N'中興', 1002, 200,1      union all   select N'中興', 1002, 200,2   select * from @InvoiceListMaster   DELETE A   from (   select rown = ROW_NUMBER( )over( partition by companyname,   invoicenumber,   customerNumber    order by companyname,   invoicenumber,   customerNumber ),   companyname,   invoicenumber,   customerNumber   from @InvoiceListMaster )a   where exists ( select 1    from ( select rown = ROW_NUMBER( )over( partition by companyname,   invoicenumber,   customerNumber    order by companyname,   invoicenumber,   customerNumber ),   companyname,   invoicenumber,   customerNumber   from @InvoiceListMaster ) b   where b.companyName = a.companyName   and b.invoiceNumber = a.invoiceNumber   and b.CustomerNumber = a.CustomerNumber   and a.rown > b.rown   )   select * from @InvoiceListMaster 

以上的例子就示範了SQL Server資料庫刪除資料集中重複資料的過程，希望本次的介紹能夠對您有所收穫！