SELECT "user"."id" AS "id", "user"."username" AS "username",
 (SELECT string_agg(region_name, ',') AS region_name
    FROM (SELECT DISTINCT region_name
           FROM auth.entity
           INNER JOIN auth.user_entity on entity.id = user_entity.entity_id
           AND "user".id = auth.user_entity.user_id) users) AS "regionName"
           FROM auth.[user] "user"
           WHERE "user".id = 12
         )
  )