gistfile1.txt

select CONCAT(ca.first_name, ' ', ca.last_name) as name, a.number, a.phoneable_id as a_id, b.phoneable_id as b_id
 FROM phone_numbers a, phone_numbers b, customers ca, customers cb
 WHERE
 a.id < b.id
 AND a.number = b.number
 AND a.phoneable_id != b.phoneable_id

 AND a.phoneable_type = 'Customer'
 AND a.phoneable_id = ca.id

 AND b.phoneable_type = 'Customer'
 AND b.phoneable_id = cb.id
 AND a.number != '5555555555'
 AND a.number != '9999999999'
 AND a.id > 967

 AND LOWER(ca.last_name) = LOWER(cb.last_name)
 AND LOWER(ca.first_name) = LOWER(cb.first_name)
 LIMIT 1