diff options
Diffstat (limited to 'lib/sqlalchemy/orm/util.py')
| -rw-r--r-- | lib/sqlalchemy/orm/util.py | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/lib/sqlalchemy/orm/util.py b/lib/sqlalchemy/orm/util.py index 886ae9a11..c9437d1b2 100644 --- a/lib/sqlalchemy/orm/util.py +++ b/lib/sqlalchemy/orm/util.py @@ -935,17 +935,38 @@ class LoaderCriteriaOption(CriteriaOption): @event.listens_for("do_orm_execute", session) def _add_filtering_criteria(execute_state): - execute_state.statement = execute_state.statement.options( - with_loader_criteria( - SecurityRole, - lambda cls: cls.role.in_(['some_role']), - include_aliases=True - ) - ) - The given class will expand to include all mapped subclass and - need not itself be a mapped class. + if ( + execute_state.is_select + and not execute_state.is_column_load + and not execute_state.is_relationship_load + ): + execute_state.statement = execute_state.statement.options( + with_loader_criteria( + SecurityRole, + lambda cls: cls.role.in_(['some_role']), + include_aliases=True + ) + ) + In the above example, the :meth:`_orm.SessionEvents.do_orm_execute` + event will intercept all queries emitted using the + :class:`_orm.Session`. For those queries which are SELECT statements + and are not attribute or relationship loads a custom + :func:`_orm.with_loader_criteria` option is added to the query. The + :func:`_orm.with_loader_criteria` option will be used in the given + statement and will also be automatically propagated to all relationship + loads that descend from this query. + + The criteria argument given is a ``lambda`` that accepts a ``cls`` + argument. The given class will expand to include all mapped subclass + and need not itself be a mapped class. + + .. warning:: The use of a lambda inside of the call to + :func:`_orm.with_loader_criteria` is only invoked **once per unique + class**. Custom functions should not be invoked within this lambda. + See :ref:`engine_lambda_caching` for an overview of the "lambda SQL" + feature, which is for advanced use only. :param entity_or_base: a mapped class, or a class that is a super class of a particular set of mapped classes, to which the rule @@ -1028,7 +1049,8 @@ class LoaderCriteriaOption(CriteriaOption): # if options to limit the criteria to immediate query only, # use compile_state.attributes instead - self.get_global_criteria(compile_state.global_attributes) + if not compile_state.compile_options._for_refresh_state: + self.get_global_criteria(compile_state.global_attributes) def get_global_criteria(self, attributes): for mp in self._all_mappers(): |