IF' in 'SELECT' statement - choose output value based on column values?

Question

SELECT id, amount FROM report I need `amount` to be `amount` if `report.type='P'` and `-amount` if `report.type='N'`. How do I add this to the above query?

Answer 1

If I am understanding the question correctly, you are looking for the following:

SELECT id, CASE

WHEN type = 'P' THEN amount

WHEN type = 'N' THEN -amount

ELSE amount END

FROM report