gistfile1.txt

SELECT "users".* FROM "users" 
  INNER JOIN "addresses" ON "addresses"."user_id" = "users"."id" 
  INNER JOIN "addresses" "countries_users_join" ON "users"."id" = "countries_users_join"."user_id" 
  INNER JOIN "countries" ON "countries"."id" = "countries_users_join"."country_id" 
  INNER JOIN "interests_users" ON "users"."id" = "interests_users"."user_id" 
  INNER JOIN "interests" ON "interests"."id" = "interests_users"."interest_id" 
WHERE 
  ("users"."level" BETWEEN 1 AND 45)
    AND ("users"."date_of_birth" BETWEEN '1986-02-09' AND '1991-02-09') 
    AND ("countries"."title" ILIKE '%d%') 

User.find_by_sql(sql).map(&:id) # => [539, 539, 539, 539] 

========================================================

SELECT "users".* FROM "users" 
  INNER JOIN "addresses" ON "addresses"."user_id" = "users"."id" 
  INNER JOIN "addresses" "countries_users_join" ON "users"."id" = "countries_users_join"."user_id" 
  INNER JOIN "countries" ON "countries"."id" = "countries_users_join"."country_id" 
WHERE 
  ("users"."level" BETWEEN 1 AND 45)
    AND ("users"."date_of_birth" BETWEEN '1986-02-09' AND '1991-02-09') 
    AND ("countries"."title" ILIKE '%d%') 
)

User.find_by_sql(sql).map(&:id) # => [500, 539, 584]