text: CREATE TABLE IF NOT EXISTS submissions (
      id              bigserial   PRIMARY KEY,
      created_at      timestamp   NOT NULL DEFAULT NOW(),
  
      score           int         NOT NULL DEFAULT 0,
      lang            lang_type   NOT NULL,
      status          status_type NOT NULL DEFAULT 'waiting',
      message         text        NOT NULL DEFAULT '',
      
      source_code text NOT NULL DEFAULT '',
      has_compile_error bool NOT NULL DEFAULT false,
  
      problem_id      int         NOT NULL REFERENCES problems(id) ON DELETE CASCADE,
      user_id         int         NOT NULL REFERENCES users(id) ON DELETE CASCADE
  );