Function make_transient_to_detached

lib/sqlalchemy/orm/session.py:5411–5447

Make the given transient instance :term:`detached`. .. note:: :func:`.make_transient_to_detached` is a special-case function for advanced use cases only. All attribute history on the given instance will be reset as though the instance were freshly loaded from a que

(instance: object)

def make_transient_to_detached(instance: object) -> None:
    """Make the given transient instance :term:`detached`.

    .. note::

        :func:`.make_transient_to_detached` is a special-case function for
        advanced use cases only.

    All attribute history on the given instance
    will be reset as though the instance were freshly loaded
    from a query.  Missing attributes will be marked as expired.
    The primary key attributes of the object, which are required, will be made
    into the "key" of the instance.

    The object can then be added to a session, or merged
    possibly with the load=False flag, at which point it will look
    as if it were loaded that way, without emitting SQL.

    This is a special use case function that differs from a normal
    call to :meth:`.Session.merge` in that a given persistent state
    can be manufactured without any SQL calls.

    .. seealso::

        :func:`.make_transient`

        :meth:`.Session.enable_relationship_loading`

    """
    state = attributes.instance_state(instance)
    if state.session_id or state.key:
        raise sa_exc.InvalidRequestError("Given object must be transient")
    state.key = state.mapper._identity_key_from_state(state)
    if state._deleted:
        del state._deleted
    state._commit_all(state.dict)
    state._expire_attributes(state.dict, state.unloaded)


def object_session(instance: object) -> Optional[Session]: