Question

SELECT users.email FROM users
INNER JOIN orders
ON orders.user_id = users.id
WHERE orders.status = 'new'
AND orders.date_created > three months back?

I would like to grab all users email that have NOT made an order on my site within 3 months from today. So if no order within 3 months, grab the email.

date_created is type TIMESTAMP. So an example is: 2012-11-10 23:54:20

Also I would like an query for grabbing users email who have not made any orders at all (no rows in orders table)?

I tried with:

SELECT users.email FROM users
    WHERE users.id NOT IN (select user_id from orders where user_id = users.id and orders.status = 'new')

But it seems to grab users with orders anyway?

Answer 1

1. I would like to grab all users email that have NOT made an order on my site within 3 months from today.

   Group the orders by user and filter the results for those where the most recent order is more than 3 months ago:

   SELECT   users.email
   FROM     users JOIN orders ON orders.user_id = users.id
   GROUP BY orders.user_id
   HAVING   MAX(orders.date_created) < CURRENT_DATE - INTERVAL 3 MONTH;
   

2. Also I would like an query for grabbing users email who have not made any orders at all (no rows in orders table)?

   Make an outer join and filter for records that fall outside of the intersection:

   SELECT   users.email
   FROM     users LEFT JOIN orders ON orders.user_id = users.id
   WHERE    orders.user_id IS NULL