select c.*,cd.* FROM
 (select * from
 (select con.id_contact as v,substr(concat(ifnull(con.firstname,''),ifnull(con.lastname,'')),1,4) as s0, null as s1, null as s2
 from contact con where id_user=123 and firstname != '' and firstname != ' ' and firstname is not null) as tbl235768 where 1=1 AND v IN
 (select v from
   (select * from
      (select con.id_contact as v,substr(concat(ifnull(con.firstname,''),ifnull(con.lastname,'')),1,4) as s0, null as s1, null as s2
      from contact con where id_user=123 and email = '') as tbl235770 where 1=1) as tblAnd) AND v IN
      (select v from
          (select * from (select con.id_contact as v,substr(concat(ifnull(con.firstname,''),ifnull(con.lastname,'')),1,4) as s0, null as s1, null as s2
          from contact con where id_user=123 and mobile != '' and mobile != ' ' and mobile is not null) as tbl235772 where 1=1) as tblAnd)) as tblBucket
          left join contact c on c.id_contact=v left join
          (select id_contact, group_concat(name) as custom_names,group_concat(value) as custom_values FROM contact_data where
          id_user=20 group by id_contact) as cd on cd.id_contact=c.id_contact group by (c.id_contact)

select id_contact, group_concat(name) as custom_names,group_concat(value) as custom_values
 FROM contact_data where id_user=798 group by id_contact