Hey...

I am writing a rather complex query that uses several conditional satements. Below is what seems to be my trouble area. These conditions are in the select. If I just select these as NULL, the query is much faster. I thought the problem was with the first line (the convert). Comment it out had very little effect. Is there another way to perform these conditions that won't make my query so inefficient?

I appreciate any help I can get.

Thanks!

(if p.fldType = 1 then right('0000' + convert(char(4), so.fldSignYear), 4) || '-' || right('00' + convert(char(2), so.fldSignMonth), 2) || '-' || right('00' + convert(char(2), so.fldSignDay), 2) else NULL endif) as fldSOSignDate,
                (if p.fldType = 1 then so.fldInvoiceNo else NULL endif) as fldInvoiceNo,
                (if p.fldType = 1 then so.fldVehicleType else NULL endif) as fldSOVehicleType,
                (if p.fldType = 1 then so.fldTechID else NULL endif) as fldTechID,
                (if p.fldType = 1 then so.fldSplitTechID else NULL endif) as fldSplitTechID,
                (if p.fldType = 1 then so.fldVIN else NULL endif) as fldSOVIN,
                    (if p.fldType = 1 then sos.fldCarPrice else NULL endif) as fldCarPayroll,
                    (if p.fldType = 1 then sos.fldTruckPrice else NULL endif) as fldTruckPayroll,
                    (if p.fldType = 1 then sov.fldVehicleType else NULL endif) as fldSOVVehicleType,
                    (if p.fldType = 1 then sov.fldVIN else NULL endif) as fldSOVVIN,
                    (if p.fldType = 1 then sos.fldsid else NULL endif)

What's p.fldType? What other values will there be? Can you just select that column, along with the others, and have the caller decide whether to use them?

Or, use a stored procedure, declare a @FieldType int variable, and set it to be either 1 or NULL. Then select so.fldInvoiceNo * @FieldType, which if it's 1, will be the same value, and if it's NULL, will return NULL.