__init__.py 文件源码

def versions(self, before=None, after=None, return_query=False):
        """Fetch the history of the given object from its history table.

        :param before: Return changes only _before_ the provided ``DateTime``.
        :param before: Return changes only _after_ the provided ``DateTime``.
        :param return_query: Return a SQLAlchemy query instead of a list of models.
        :return: List of history models for the given object (or a query object).
        """
        # get the primary keys for this table
        prim_keys = [k.key for k in self.__history_mapper__.primary_key if k.key != 'version']

        # Find all previous versions that have the same primary keys as myself
        query = self.__history_mapper__.class_.query.filter_by(
            **{k: getattr(self, k) for k in prim_keys}
        )

        # Filter additionally by date as needed
        if before is not None:
            query = query.filter(self.__history_mapper__.class_.changed <= before)
        if after is not None:
            query = query.filter(self.__history_mapper__.class_.changed >= after)

        # Order by the version
        query = query.order_by(self.__history_mapper__.class_.version)

        if return_query:
            return query
        else:
            return query.all()