SQL Server数据库删除数据集中重复数据实例讲解
SQLServer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@InvoiceListMastertable(IDintidentityprimarykey, companyNameNchar(20), invoiceNumberint, CustomerNumberint, rmaNumberint) insert@InvoiceListMaster selectN'华为',1001,100,200 unionall selectN'华为',1001,100,300 unionall selectN'华为',1001,100,301 unionall selectN'中兴',1002,200,1 unionall selectN'中兴',1002,200,2 select*from@InvoiceListMaster DELETEA from( selectrown=ROW_NUMBER()over(partitionbycompanyname, invoicenumber, customerNumber orderbycompanyname, invoicenumber, customerNumber), companyname, invoicenumber, customerNumber from@InvoiceListMaster)a whereexists(select1 from(selectrown=ROW_NUMBER()over(partitionbycompanyname, invoicenumber, customerNumber orderbycompanyname, invoicenumber, customerNumber), companyname, invoicenumber, customerNumber from@InvoiceListMaster)b whereb.companyName=a.companyName andb.invoiceNumber=a.invoiceNumber andb.CustomerNumber=a.CustomerNumber anda.rown>b.rown ) select*from@InvoiceListMaster
以上的例子就演示了SQLServer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！