SQL server : Usage of "in" clause in "If" condition

                    I had a situation to pass multi-value parameter into SSRS data set and execute a query if the multi value parameter contains a value -'ABC' else execute another one query  (to put it in simple form) ..So i tried using the following syntax:


If @Param1 in ('ABC')  
Select  a,b from Table1


else 
select b,c from Table1
End



 we got surprised when the above syntax didn't work as expected..Then we identified the trick over the SQL syntax :

The IN clause should be in reverse order when it has been used in IF Conditions:


If @Param1 'ABC' in (@Param1)


Select  a,b from Table1


else 
select b,c from Table1
End

Then it started working fine..!