Rsa97

$res = array();
while ($res = mysql_fetch_array($query))
    $res[] = array('family'=>$res['family'], 'name'=>$res['name']);
echo json_encode($res);

SELECT  `t`.`action_ID`, `t1`.`prov_title` AS `prov_title_A`, `t1`.`track_no` AS `track_no_A`,
       `t2`.`prov_title` AS `prov_title_B`, `t2`.`track_no` AS `track_no_B`, 
       `t3`.`prov_title` AS `prov_title_C`, `t3`.`track_no` AS `track_no_C`
  FROM (
    SELECT DISTINCT `action_ID`
      FROM `action_has_providers`
  ) AS `t`
  LEFT JOIN `action_has_providers` AS `t1` 
    ON `t1`.`action_ID` = `t`.`action_ID` AND `t1`.`prov_title` = 'ProvA'
  LEFT JOIN `action_has_providers` AS `t2` 
    ON `t2`.`action_ID` = `t`.`action_ID` AND `t2`.`prov_title` = 'ProvB'
  LEFT JOIN `action_has_providers` AS `t3` 
    ON `t3`.`action_ID` = `t`.`action_ID` AND `t3`.`prov_title` = 'ProvC'

SELECT `u`.*
  FROM `users` AS `u`
  JOIN `user_tags` AS `ut` ON `ut`.`user_id` = `u`.`id`
    AND `ut`.`tag_id` IN (1, 2, ..., N)
  GROUP BY `u`.`id`
  HAVING COUNT(*) = N

SELECT `u`.*
  FROM `users` AS `u`
  JOIN `user_tags` AS `ut` ON `ut`.`user_id` = `u`.`id`
    AND `ut`.`tag_id` IN (1, 2, ..., N)
  GROUP BY `u`.`id`
  HAVING COUNT(DISTINCT `ut`.`tag_id`) = N

CREATE FUNCTION SearchRoot(id INT)
BEGIN
  DECLARE parent INT;
  SET parent = id;
  REPEAT
    SET id = parent;
    SET parent = (SEARCH `id_parent` FROM `table` WHERE `id` = id);
  UNTIL parent > 0 END REPEAT;
  RETURN id;
END