Mělo by to stačit:
select income, expense, income-expense balance
from (select sum(rate) income
from _income) i
JOIN (select sum(rate) expense
from _expense) e
Mělo by to stačit:
select income, expense, income-expense balance
from (select sum(rate) income
from _income) i
JOIN (select sum(rate) expense
from _expense) e