Question

This Query is giving me an error of #1054 – Unknown column ‘totalamount’ in ‘where clause’

 SELECT (amount1 + amount2) as totalamount 
 FROM `Donation` 
 WHERE totalamount > 1000

I know i can resolve this error by using group by clause and replace my where condition with having clause. But is there any other solution beside using having clause. If group by is the only solution then I want to know why I have to use group by clause even I havent use any aggregate function

thanks.

Answer 1

I would not expect MySQL to give that error message, but many other databases do. In other databases you can work around it by repeating the column definition:

SELECT  amount1 + amount2 as totalamount 
FROM    Donation
WHERE   amount1 + amount2 > 1000

Or you can use a subquery to avoid the repitition:

SELECT  totalamount 
FROM    (
        select  amount1 + amount2 as totalamount
        ,       *
        from    Donation
        ) as SubQueryAlias
WHERE   totalamount  > 1000

Live example at SQL Fiddle.