code: def query_form_data(self):
          
          form_data = {}
          slice_id = request.args.get('slice_id')
          if slice_id:
              slc = db.session.query(models.Slice).filter_by(id=slice_id).one_or_none()
              if slc:
                  form_data = slc.form_data.copy()
  
          update_time_range(form_data)
  
          return json.dumps(form_data)
docs: Get the formdata stored in the database for existing slice.
          params: slice_id: integer