Question

Here are my two tables

users
------------------------
id username name surname
2  Foo       f     b
4  Bar       b     f

orders
---------------------
id user_id price qty
1  2       3.2   1
2  4       6     4
etc ...

And here is how my query looks like

SELECT
    u.name,
    u.surname,
    COUNT(r.user_id) as total,
    SUM(r.price) as total_price,
FROM orders r
    LEFT JOIN users u on u.id = r.user_id
    WHERE order_id  = 4 
GROUP BY user_id

Thus I get total of money that user is spent.
The problem is that the calculation is wrong because the user can be bought more than one item of product.
I can’t figure out how to do so calculation to include and quanity.

Answer 1

You can try to multiply and sum, like :-

sum(r.price * r.qty) as total_price