SQL Server数据库删除数据集中重复数据实例讲解

SQL Server数据库操作中,有时对于表中的结果集,满足一定规则我们则认为是重复数据,而这些重复数据需要删除。如何删除呢?本文我们通过一个例子来加以说明。

例子如下:

如下只要companyName,invoiceNumber,customerNumber三者都相同,我们则认为是重复数据,下面的例子演示了如何删除。

insert @InvoiceListMaster

select N’华为’,1001,100,200

union all

select N’华为’,300

union all

select N’华为’,301

union all

select N’中兴’,1002,200,1

union all

select N’中兴’,2

select * from @InvoiceListMaster

DELETE A

from (

select rown = ROW_NUMBER( )over( partition by companyname,invoicenumber,customerNumber

order by companyname,customerNumber ),companyname,customerNumber

from @InvoiceListMaster )a

where exists ( select 1

from ( select rown = ROW_NUMBER( )over( partition by companyname,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

以上的例子就演示了SQL Server数据库删除数据集中重复数据的过程,希望本次的介绍能够对您有所收获!

dawei

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