SELECT * 
FROM distributors_users_assignment
LEFT JOIN users ON distributors_user_ID = users_ID
LEFT JOIN orders ON orders_users_ID = users_ID
WHERE distributors_ua_distributor_ID =  '86'
AND users.users_last_contact_made IS NOT NULL 
AND users.users_relationship =  '3'
AND orders.orders_date_purchased > DATE_ADD(NOW(), INTERVAL -30 DAY)
GROUP BY users.users_ID