'IF' in 'SELECT' statement - choose output value based on column values
SELECT CompanyName,
CASE WHEN Country IN ('USA', 'Canada') THEN 'North America'
WHEN Country = 'Brazil' THEN 'South America'
ELSE 'Europe' END AS Continent
FROM Suppliers
ORDER BY CompanyName;
Use a case
statement:
select id,
case report.type
when 'P' then amount
when 'N' then -amount
end as amount
from
`report`
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.
select
id,
case
when report_type = 'P'
then amount
when report_type = 'N'
then -amount
else null
end
from table