You can use the CASE statement for this:
CASE WHEN [EmployeeTypeID] IN (10, 12) THEN [SumOfBillable_Hours] / 9,
ELSE 'NA' END
Just make sure that the data type that will be returned for both cases are compatible to each other. Otherwise you will get an error message.
SQL Server Helper
How well do you know SQL? Find out with the free test assessment from SQL Server Helper!!!
http://www.sql-server-helper.com/free-test/default.aspx
Got a SQL Server Question? Ask us here:
http://www.sql-server-helper.com/forums/default.asp