Convertion to Ecto query from sql

I have a sql query with a join and NOT EXITS as follows

select name, email, nickname, lastname, firstname, phone 
 from a join b on and a.s_id = 2 where NOT EXISTS
 select c.team_id from c
 where c.s_id = 1
 and c.round_id = 2
 and = c.user_id

I want to convert it into Ecto query… Can some one help me with it?

from a in "a",
  select: [:name, :email, :nickname, :lastname, :firstname, :phone],
  inner_join: b in "b", on: a.user_id = and a.s_id = 2,
  left_join: c in "c", on: c.s_id = 1 and c.round_id = 2 and = c.user_id,
  where: is_nil(