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 openingbalance, similar to this Select Case block in Access VBA:

Select Case OpeningBalance    Case 0 To 5000         commission = 20    Case 5001 To 10000         commission = 30    Case 10001 To 20000         commission = 40    Case Else         commission = 50 End Select 

But since Access doesn't allow Select Case in a query, how can I accomplish my goal in Access SQL?

Answer 1

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.