I have data fields Date_Req Date_Del Del_Qty What I am wanting to do is write an expression so that if the Date_Del is either more than 3 days eairlier than the Date_Req or more that 3 dates later than the Date_req it would result zero if not it would result Del_Qty Can anyone help

For performance reasons this should be written in your sql dataset query rather than a report layer expression, calculations are what the sql engine is designed for. something like: SELECT Date_Req ,Date_Del ,Del_Qty ,New_Field = CASE WHEN ABS(datediff(d, Date_Req, Date_Del)) > 3 THEN 0 ELSE DelQty END FROM MyTable My Blog "Karl Beran's BI Mumble"

Many thanks. The reason I was trying to avoid doing the calculation in SQL is that this criteria differs for different customers and therefore I was going to build this into the formula

Should still be done in SQL, if customer is a parameter in the report pass it through to the CASE statement.My Blog "Karl Beran's BI Mumble"

so say the customer data field is called cust_no & cust_no 999 is based on the criteria already mentioned and cust_no 888 is 10 days earlier and zero days later how would I use the case?

SELECT Date_Req ,Date_Del ,Del_Qty ,New_Field = CASE WHEN cust_no = 999 AND ABS(datediff(d, Date_Req, Date_Del)) > 3 THEN 0 WHEN cust_no = 999 AND ABS(datediff(d, Date_Req, Date_Del)) > 10 THEN 0 ELSE DelQty END FROM MyTable or if you had the values 3 and 10 in a customer table as follows cust_no days 999 3 888 10 then you could do the following: SELECT Date_Req ,Date_Del ,Del_Qty ,New_Field = CASE WHEN ABS(datediff(d, Date_Req, Date_Del)) > c.days THEN 0 ELSE DelQty END FROM MyTable t INNER JOIN MyCustomers c ON t.cust_no = c.cust_no My Blog "Karl Beran's BI Mumble"

Thanks