message: [hotfix] 'NoneType' object has no attribute 'upper'
diff: @@ -114,7 +114,7 @@ class TableColumn(Model, BaseColumn):
  return str((dttm - datetime(1970, 1, 1)).total_seconds() * 1000.0)
  else:
  s = self.table.database.db_engine_spec.convert_dttm(
  - self.type, dttm)
  + self.type or '', dttm)
  return s or "'{}'".format(dttm.strftime(tf))
  