Method merge_result

lib/sqlalchemy/orm/query.py:3003–3035

Merge a result into this :class:`_query.Query` object's Session. Given an iterator returned by a :class:`_query.Query` of the same structure as this one, return an identical iterator of results, with all mapped instances merged into the session using :meth:`.Session.

(
        self,
        iterator: Union[
            FrozenResult[Any], Iterable[Sequence[Any]], Iterable[object]
        ],
        load: bool = True,
    )

        enable_warnings=False,  # warnings occur via loading.merge_result
    )
    def merge_result(
        self,
        iterator: Union[
            FrozenResult[Any], Iterable[Sequence[Any]], Iterable[object]
        ],
        load: bool = True,
    ) -> Union[FrozenResult[Any], Iterable[Any]]:
        """Merge a result into this :class:`_query.Query` object's Session.

        Given an iterator returned by a :class:`_query.Query`
        of the same structure
        as this one, return an identical iterator of results, with all mapped
        instances merged into the session using :meth:`.Session.merge`. This
        is an optimized method which will merge all mapped instances,
        preserving the structure of the result rows and unmapped columns with
        less method overhead than that of calling :meth:`.Session.merge`
        explicitly for each value.

        The structure of the results is determined based on the column list of
        this :class:`_query.Query` - if these do not correspond,
        unchecked errors
        will occur.

        The 'load' argument is the same as that of :meth:`.Session.merge`.

        For an example of how :meth:`_query.Query.merge_result` is used, see
        the source code for the example :ref:`examples_caching`, where
        :meth:`_query.Query.merge_result` is used to efficiently restore state
        from a cache back into a target :class:`.Session`.

        """

        return loading.merge_result(self, iterator, load)

    def exists(self) -> Exists:
        """A convenience method that turns a query into an EXISTS subquery