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  • full join 时通过辅助列序号列消除笛卡尔积重复列

    如果没有序号列,那么如果领灯表里有3条数据,还灯表里面有2条数据,full join后就是3*2=6条数据

    --1、领灯表,每天每班每人允许重复数据
    select ID
          ,ROW_NUMBER() over(partition by PersonID,classid,dt_ClassData order by id)  as  getnum
          ,[PersonID]
          ,[ClassID]
          ,[dt_GetTime]
          ,[dt_ClassData]
    from   m_LampHistoryDataGet as a
    order by  PersonID,dt_GetTime

    --2、还灯表,每天每班每人允许重复数据
    select ID
          ,ROW_NUMBER() over(partition by PersonID,classid,dt_ClassData order by id)  as  getnum
          ,[PersonID]
          ,[ClassID]
          ,[dt_ReturnTime]
          ,[dt_ClassData]
    from   v_LampHistoryDataReturn as a
    order by  PersonID,dt_ReturnTime
    
    --3、整合表,要求领灯时间与还灯时间按照顺序一一对应,第一条领灯数据对应第一条还灯数据
    SELECT 
          laGet.id as GetID
          ,laReturn.ID as ReturnID
          ,coalesce(laGet.getnum,laReturn.returnnum) as num
          ,coalesce(laGet.PersonID,laReturn.PersonID) as PersonID  
          ,laGet.[dt_GetTime]
          ,laReturn.dt_ReturnTime
          ,coalesce(laGet.ClassID,laReturn.ClassID) as classid
          ,coalesce(laGet.dt_ClassData,laReturn.dt_ClassData) as dt_ClassData
          
    FROM         dbo.v_LampHistoryDataGet AS laGet 
    full join dbo.v_LampHistoryDataReturn  laReturn 
    on  laGet.PersonID=laReturn.PersonID 
    and laGet.dt_ClassData=laReturn.dt_ClassData 
    and laGet.ClassID=laReturn.ClassID
    and  laGet.getnum= laReturn.returnnum
    order by  PersonID,coalesce(dt_GetTime,dt_ReturnTime) 
    --按照人员,领灯时间排序
    END 
    
      
    

      

    ..

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  • 原文地址:https://www.cnblogs.com/xiaochun126/p/4226646.html
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