连接两个表，结果两次 [英] joining two table and result come twice in result

问题描述

我的查询中有一条select命令，该命令从两个表中获取数据，结果的每一行都出现两次result，我的查询是

i have a select command in my query that fetch data from two table , and each row of result come twice in result , my query is

Select  
  Driver.DriverID,
  Driver.FName,
  Driver.LName,
  Driver.SmartCardNumber,
  Driver.DriverState,
  Driver.DriverCity,
  Driver.DriverAddress,
  Driver.Mobile,
  Driver.Telephone,
  Driver.MelliCardNumber, 
  Driver.CertificatePublisher,
  Driver.addeddate,
  Driver.ContractorID,
  Driver.editeddate,
  Contractor.name  
From Driver,Contractor

推荐答案

如果Driver和Contractor表之间存在关系，则需要满足条件.

you need where condition if Driver and Contractor tables have relationship between them.

类似

Select  
  Driver.DriverID,
  Driver.FName,
  Driver.LName,
  Driver.SmartCardNumber,
  Driver.DriverState,
  Driver.DriverCity,
  Driver.DriverAddress,
  Driver.Mobile,
  Driver.Telephone,
  Driver.MelliCardNumber, 
  Driver.CertificatePublisher,
  Driver.addeddate,
  Driver.ContractorID,
  Driver.editeddate,
  Contractor.name  
From Driver,Contractor
    where Driver.ContractorID = Contractor.id

假设ContractorID链接到Contractor的ID.

assuming ContractorID is linked to the id of Contractor.

这篇关于连接两个表，结果两次的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！