create table movie_showtimes (
  id integer not null
    default nextval('movie_showtimes_id_seq'),
  movie_id integer not null 
    references movies(id),
  theatre_id integer not null 
    references theatres(id),
  auditorium varchar(16) not null 
    check (length(auditorium) > 0),
  start_time timestamp with time zone not null,
  primary key (id)
);

