SQL从结果中删除重复项

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当SQL添加“备用审批人”（针对采购订单）时，它会为实际审批人创建一条附加记录。因此，试图找到一种方法，为那些也有备选方案的审批人只显示一条记录。i、 e.“jlhayes”有2项记录。一个有替补，一个没有。对于这些记录，我只想查看有备用记录的记录。谢谢您的帮助。我已经花了几个小时没有想法了。

你可以在

max（AltApprover）

中包装

AltApprover

案例陈述，并按

DAC.LocationCode、DAC.Description、requapp.Rank、App.Approver

分组，对

FromDate

和

ToDate

也可以这样做：

select DAC.LocationCode, DAC.Description, ReqApp.Rank, App.Approver as UserName,
CASE WHEN app.Approver = app.AlternateApprover THEN '' 
ELSE AltApp.AlternateApprover END As AltApprover, 
ISNULL(CONVERT(Varchar,AltApp.FromDate,101),'')AS FromDate,
ISNULL(CONVERT(Varchar,AltApp.ToDate,101),'')AS ToDate
from tblAPAlternateApprovers App
INNER JOIN tblAPAlternateApprovers AltApp
ON App.ID = AltApp.ID
INNER JOIN tblAPReqLocations DAC
ON App.tblAPReqLocationsID = DAC.ID
INNER JOIN tblAPReqApprover ReqApp
ON App.Approver = ReqApp.Approver AND 
App.tblAPReqLocationsID = ReqApp.LocationID
ORDER BY DAC.LocationCode ASC, ReqApp.Rank asc

select DAC.LocationCode, DAC.Description, ReqApp.Rank, App.Approver as UserName,
max(CASE WHEN app.Approver = app.AlternateApprover THEN '' 
ELSE AltApp.AlternateApprover END) As AltApprover, 
max(ISNULL(CONVERT(Varchar,AltApp.FromDate,101),'')) AS FromDate,
max(ISNULL(CONVERT(Varchar,AltApp.ToDate,101),'')) AS ToDate
from tblAPAlternateApprovers App
INNER JOIN tblAPAlternateApprovers AltApp
ON App.ID = AltApp.ID
INNER JOIN tblAPReqLocations DAC
ON App.tblAPReqLocationsID = DAC.ID
INNER JOIN tblAPReqApprover ReqApp
ON App.Approver = ReqApp.Approver AND 
App.tblAPReqLocationsID = ReqApp.LocationID
GROUP BY DAC.LocationCode, DAC.Description, ReqApp.Rank, App.Approver
ORDER BY DAC.LocationCode ASC, ReqApp.Rank asc