Sql server datatype values issue

Question

Hi,

I have come across a strange scenario while executing a query. I was surprised by the way Sql Server was executing the query.

Quote:

SELECT TOP 10 MR.MerchantContactFirstName + ' ' + MR.MerchantContactLastName AS MerchantName,
AISLTrans.DeviceID,AISLTrans.TransactionID, AISLTrans.CardNumber, AISLTrans.TransactionDateTime,
AISLTrans.TransactionStatus, AISTRNSTYPE.TransactionType AS TransactionRequestType,AISLTrans.TransactionAmount,
(AISLTrans.BasePointEarn+AISLTrans.BonusPointEarn)AS 'Point Awarded'
FROM AISLoyaltyTransactions AISLTrans INNER JOIN
MerchantRegistration MR
ON AISLTrans.MerchantID = MR.MerchantID INNER JOIN
AISTransactionTypes AISTRNSTYPE
ON AISLTrans.ProcessingCode = AISTRNSTYPE.ProcessingCode AND
AISLTrans.TransactionType = AISTRNSTYPE.MessageType WHERE AISLTrans.TransactionType = 0200
AND AISLTrans.ProcessingCode = 071000 ORDER BY AISLTrans.TransactionDateTime DESC

In above query the field ISLTrans,TransactionType works fine for all the values except 0200 it accepts all interger values though the field type is of varchar.

But when I give the value as 0200 it throws exception saying cannot convert varchar to int.

I am looking for why the query is still executing though I am providing integer value instead of varchar and if it is executing why its not accepting all the integer values which I provide.

Thanks,
Praveen Nelge