text: SELECT
      users.user_id,
      users.alias,
      users.email,
      users.date_of_birth,
      users.gender,
      users.country,
      f1.date_send,
      f1.date_accepted,
      f1.date_canceled,
      f2.date_send,
      f2.date_accepted,
      f2.date_canceled
  FROM users
  LEFT JOIN friendships AS f1
      ON users.user_id = f1.receiver_user_id
      AND f1.sender_user_id = :self_id
  LEFT JOIN friendships AS f2
      ON users.user_id = f2.sender_user_id
      AND f2.receiver_user_id = :self_id
  WHERE
      users.alias LIKE :search
      AND NOT users.user_id = :self_id
  LIMIT 50