Method flush

lib/sqlalchemy/orm/session.py:4323–4355

Flush all the object changes to the database. Writes out all pending object creations, deletions and modifications to the database as INSERTs, DELETEs, UPDATEs, etc. Operations are automatically ordered by the Session's unit of work dependency solver. Datab

(self, objects: Optional[Sequence[Any]] = None)

        return state in self._new or self.identity_map.contains_state(state)

    def flush(self, objects: Optional[Sequence[Any]] = None) -> None:
        """Flush all the object changes to the database.

        Writes out all pending object creations, deletions and modifications
        to the database as INSERTs, DELETEs, UPDATEs, etc.  Operations are
        automatically ordered by the Session's unit of work dependency
        solver.

        Database operations will be issued in the current transactional
        context and do not affect the state of the transaction, unless an
        error occurs, in which case the entire transaction is rolled back.
        You may flush() as often as you like within a transaction to move
        changes from Python to the database's transaction buffer.

        :param objects: Optional; restricts the flush operation to operate
          only on elements that are in the given collection.

          This feature is for an extremely narrow set of use cases where
          particular objects may need to be operated upon before the
          full flush() occurs.  It is not intended for general use.

        """

        if self._flushing:
            raise sa_exc.InvalidRequestError("Session is already flushing")

        if self._is_clean():
            return
        try:
            self._flushing = True
            self._flush(objects)
        finally:
            self._flushing = False

    def _flush_warning(self, method: Any) -> None:
        util.warn(