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。

declare @InvoiceListMaster table ( ID int identity primary key ,

companyName Nchar(20),

invoiceNumber int,

CustomerNumber int,

rmaNumber int )

insert @InvoiceListMaster

select N'华为', 1001,100,200

union all

select N'华为', 1001,100,300

union all

select N'华为', 1001,100,301

union all

select N'中兴', 1002, 200,1

union all

select N'中兴', 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！