Question

I have two tables.

User table has user_id and order_num

Orders table has order_num, dd, mm, yyyy, order_detail.

When a user wants to see all orders for a certain month I usually select order_num from user table where user_id matches a cookie, then while loop and within the loop do a select on orders table matching order_num and displaying if month matches month selected.

Is there a more efficient way to do this? With a join of some sort? Quite basic sql knowledge but keen to expand

So, I currently do (i know its not good code but logical sql most important part of this question, i know how to code correctly)

select order_num from user where user_id = $cookie

while (results) {

    select order_detail, mm, dd, yyyy where mm = $month

    echo order_detail mm dd yyyy

    }

Answer 1

Sure, you can do something like:

SELECT * FROM users u
JOIN orders o ON u.order_num = o.order_num AND o.mm = ###
WHERE u.user_id = ###