text: drop table if exists submissions;
  drop type if exists access_type;
  
  create type access_type as enum ('public', 'limited');
  create table submissions (
  	submission_id		serial primary key,
  	collection_code 	text references collection_codes(collection_code),
  	site_code			text references site_codes(site_code),
      patient_id_prefix   text,
      body_part           text,
      access_type         access_type,
      baseline_date       timestamp,
      date_shift          integer,
      unique (collection_code, site_code)
  );
  