code: def get_db_prep_value(self, value, connection, prepared=False):
          
          log.debug("get_db_prep_value: {}, {}", value, type(value))
          value = super().get_db_prep_value(value, connection, prepared)
          if value is None:
              return value
          # log.debug("connection.settings_dict['ENGINE']: {}",
          #           connection.settings_dict['ENGINE'])
          if connection.settings_dict['ENGINE'] == 'django.db.backends.sqlite3':
              return python_utc_datetime_to_sqlite_strftime_string(value)
          return value
docs: Further conversion of Python value to database value for QUERYING.
          This follows ``get_prep_value()``, and is for backend-specific stuff.
          See notes above.