What is the equivalent of Select Case in Access SQL?

Question

I have a query which includes fields named openingbalance and commissions. I would like to compute values for commissions based on openingbala

Answer 1

You could do below:

select
iif ( OpeningBalance>=0 And OpeningBalance<=500 , 20, 

                  iif ( OpeningBalance>=5001 And OpeningBalance<=10000 , 30, 

                       iif ( OpeningBalance>=10001 And OpeningBalance<=20000 , 40, 

50 ) ) ) as commission
from table

Answer 2

You can use IIF for a similar result.

Note that you can nest the IIF statements to handle multiple cases. There is an example here: http://forums.devshed.com/database-management-46/query-ms-access-iif-statement-multiple-conditions-358130.html

SELECT IIf([Combinaison] = "Mike", 12, IIf([Combinaison] = "Steve", 13)) As Answer 
FROM MyTable;

Answer 3

Consider the Switch Function as an alternative to multiple IIf() expressions. It will return the value from the first expression/value pair where the expression evaluates as True, and ignore any remaining pairs. The concept is similar to the SELECT ... CASE approach you referenced but which is not available in Access SQL.

If you want to display a calculated field as commission:

SELECT
    Switch(
        OpeningBalance < 5001, 20,
        OpeningBalance < 10001, 30,
        OpeningBalance < 20001, 40,
        OpeningBalance >= 20001, 50
        ) AS commission
FROM YourTable;

If you want to store that calculated value to a field named commission:

UPDATE YourTable
SET commission =
    Switch(
        OpeningBalance < 5001, 20,
        OpeningBalance < 10001, 30,
        OpeningBalance < 20001, 40,
        OpeningBalance >= 20001, 50
        );

Either way, see whether you find Switch() easier to understand and manage. Multiple IIf()s can become mind-boggling as the number of conditions grows.