Question

I have a table called product and a table called sold.

I’m trying to figure out if there is a way to use one query to find all products and then for each product fond return in the result set a sum of sold.amount as total.

Answer 1

It’s a very basic SQL join operation:

select product.id, sum(sold.amount)
from product
left join sold ON product.id = sold.product_id
group by product.id

if you want to list only products which have at least one sale, then change ‘left join’ to ‘inner join’.