Question

i want to know if is possible to do something like this in mysql:

select 5 as a, 1 as b, a + b as c; 

the problem is because i have this:

CONVERT( SUM(ifnull(commission,0.00)) ,DECIMAL(6,2)) as 'commission',
CONVERT( SUM(ifnull(income,0.00)) ,DECIMAL(6,2)) as 'income',
CONVERT( (SUM(ifnull(income,0.00)) - SUM(ifnull(commission,0.00))) ,DECIMAL(6,2)) as 'profit'

and of course the 3rd line would be more optimus if it dont have to SUM all the values again.

Answer 1

You can’t do

select 5 as a, 1 as b, a + b as c;

but you can do

select a, b, a + b as c from (select 5 as a, 1 as b) as whatever;

(This is a nested query, which acts as a fake table when used from the outer query).

Applying thys to your case, we’d have:

select comission, income, income - comission from (
    select
        CONVERT( SUM(ifnull(commission,0.00)) ,DECIMAL(6,2)) as 'commission',
        CONVERT( SUM(ifnull(income,0.00)) ,DECIMAL(6,2)) as 'income'
    FROM ...
) as t

Hope this helps.