如何在PHP中获得总付款

Question

I have two tables users and payments, in payments I have user_id amount_to_pay and amount_paid. I want to get users who didn't paid full payment, so

if($payments->amount_to_pay < $payments->amount_paid)
{ $unpayments += $amount_to_pay - $amount_paid}

But the problem is that a user has many payments so I need to check how many users didn't paid full subscription.

Please Help

Answer 1

I am assuming that these tables you are talking about are in a database?

I think probably the best way to do this check is through SQL

SELECT user_id, sum(amount_paid) AS paid  FROM payments GROUP BY user_id;

if you run that query you should get a list of all the users that have made payments and the total that they have paid so you can run over the results in a while or for loop easily.