Select Distinct Help?

Can you have "Select Distinct" in Union Query,because that is what I am trying to do and this is the error message I get.

"The text, ntext, or image data type cannot be selected as DISTINCT."

I would need to do that because i have duplicate records,because these records are getting written into the db when templates are generated and sometimes if they double click it generates two and writes that many results as well, so that is why I was thinking that select distinct would solve my problem.


Thanks for your help

This is the query in question:



SELECT Distinct 'O' AS Origin, a.RecordID, a.RelocateID, a.SupplierID, a.DateIn, a.DateOut, a.NoOfDays, a.AgreeAmt, a.PaymentMethod, a.AccomType, a.Reason,
a.InvRecvd, a.RelocateeTempAccomTS, a.BedConfiguration, a.NumberOfPax, a.AdditionalItems, a.Currency, a.TotalAmount, a.EnteredBy,
a.LastModifiedBy, a.ReferenceNumber, a.Location, a.Comments, a.ArrivalTime, a.PONumber,CommissionRate, ISNULL
((SELECT TOP 1 ExchangeRateToUSD
FROM luCurrencyExchangeRates c
WHERE a.Currency = c.CurrencyID AND a.DateIn >= c.ActiveDate), 1.0) AS ForeignExchangeRate, ISNULL
((SELECT TOP 1 ExchangeRateToUSD
FROM luCurrencyExchangeRates c
WHERE 'AUD' = c.CurrencyID AND a.DateIn >= c.ActiveDate), 1.0) AS AUDExchangeRate, a.WhenConfirmed, e.RequestID AS RequestID,
e.DocumentID AS DocRequestID, e.RequestWhen AS RequestWhen, e.WhereClause AS WhereClause,
dbo.luDecisionMaker.DecisionMakerName AS DecisionMadeBy, dbo.viewZYesno.Description AS CommissionableDesc
FROM dbo.RelocateeTempAccom a LEFT OUTER JOIN
dbo.luDecisionMaker ON a.DecisionMaker = dbo.luDecisionMaker.DecisionMakerID LEFT OUTER JOIN
dbo.viewZYesno ON a.Commissionable = dbo.viewZYesno.[Value] LEFT OUTER JOIN
dbo.docRequests e ON '{RelocateeTempAccom.RecordID}=' + CONVERT(VARCHAR a.RecordID) = e.WhereClause
WHERE (ISNULL(a.Cancelled, 0) = 0)

UNION ALL

SELECT Distinct 'D' AS Origin, RecordID, RelocateID, DTASupplierID AS SupplierID, DTADateIn AS DateIn, DTADateOut AS DateOut, DTANoOfDays AS NoOfDays,
DTAAgreeAmt AS AgreeAmt, DTAPaymentMethod AS PaymentMethod, DTAAccomType AS AccomType, Reason, InvRecvd,
RelocateeDTATS AS RelocateeTempAccomTS, BedConfiguration, NumberOfPax, AdditionalItems, Currency, DailyTotal AS TotalAmount, EnteredBy,
LastModifiedBy, ReferenceNumber, Location, Comments, ArrivalTime, PONumber,CommissionRate, ISNULL
((SELECT TOP 1 ExchangeRateToUSD
FROM luCurrencyExchangeRates d
WHERE b.Currency = d .CurrencyID AND b.DTADateIn >= d .ActiveDate), 1.0) AS ForeignExchangeRate, ISNULL
((SELECT TOP 1 ExchangeRateToUSD
FROM luCurrencyExchangeRates d
WHERE 'AUD' = d .CurrencyID AND b.DTADateIn >= d .ActiveDate), 1.0) AS AUDExchangeRate, WhenConfirmed, e.RequestID AS RequestID,
e.DocumentID AS DocRequestID, e.RequestWhen AS RequestWhen, e.WhereClause AS WhereClause,
dbo.luDecisionMaker.DecisionMakerName AS DecisionMadeBy, dbo.viewZYesno.Description AS CommissionableDesc
FROM dbo.RelocateeDTA b LEFT JOIN
dbo.luDecisionMaker ON b.DecisionMaker = dbo.luDecisionMaker.DecisionMakerID LEFT JOIN
dbo.viewZYesno ON b.Commissionable = dbo.viewZYesno.[Value] LEFT OUTER JOIN
dbo.docRequests e ON '{RelocateeDTA.RecordID}=' + CONVERT(VARCHAR, b.RecordID) = e.WhereClause
WHERE ISNULL(Cancelled, 0) = 0