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?
7 s
SELECT id,
IF(type="P", amount, amount * -1) as amount
FROM report
See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of a null amount:
SELECT id,
IF(type="P", IFNULL(amount,0), IFNULL(amount,0) * -1) as amount
FROM report
The part IFNULL(amount,0)
means when amount is not null return amount else return 0.