I'm trying to use this SQL statement in DAX func. =Sum( CASE when tablename.colname in ('a','b') then -1 when tablename.colname in ('c','d') then 0 when tablename.colname in ('e','f') then 1 else 0 END) which is an ideal func to use CALCULATE() or SWITCH() ? Thanks.

Works for me maybe you are trying to use DAX code in M (Power Query) then it will throw an error on 'in' ? if that's the case then DAX functions cannot be used in M query