code: def make_views(cls, conn):
          
          conn.execute('DROP VIEW IF EXISTS main.day_trips')
          conn.execute('CREATE VIEW day_trips AS   '
                       'SELECT day_trips2.*, trips.* '
                       #'days.day_start_ut+trips.start_time_ds AS start_time_ut, '
                       #'days.day_start_ut+trips.end_time_ds AS end_time_ut   '
                       'FROM day_trips2 JOIN trips USING (trip_I);')
          conn.commit()
  
          conn.execute('DROP VIEW IF EXISTS main.day_stop_times')
          conn.execute('CREATE VIEW day_stop_times AS   '
                       'SELECT day_trips2.*, trips.*, stop_times.*, '
                       #'days.day_start_ut+trips.start_time_ds AS start_time_ut, '
                       #'days.day_start_ut+trips.end_time_ds AS end_time_ut, '
                       'day_trips2.day_start_ut+stop_times.arr_time_ds AS arr_time_ut, '
                       'day_trips2.day_start_ut+stop_times.dep_time_ds AS dep_time_ut   '
                       'FROM day_trips2 '
                       'JOIN trips USING (trip_I) '
                       'JOIN stop_times USING (trip_I)')
          conn.commit()
docs: Create day_trips and day_stop_times views.
  
          day_trips:  day_trips2 x trips  = days x trips
          day_stop_times: day_trips2 x trips x stop_times = days x trips x stop_times