diff options
Diffstat (limited to 'lib/sqlalchemy/orm/query.py')
| -rw-r--r-- | lib/sqlalchemy/orm/query.py | 94 |
1 files changed, 53 insertions, 41 deletions
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py index 18ffd108a..b22a10b55 100644 --- a/lib/sqlalchemy/orm/query.py +++ b/lib/sqlalchemy/orm/query.py @@ -32,7 +32,7 @@ from sqlalchemy.orm import ( from sqlalchemy.orm.util import ( AliasedClass, ORMAdapter, _entity_descriptor, _entity_info, _is_aliased_class, _is_mapped_class, _orm_columns, _orm_selectable, - join as orm_join, + join as orm_join,with_parent ) @@ -98,6 +98,7 @@ class Query(object): _attributes = util.frozendict() _with_options = () _with_hints = () + _enable_single_crit = True def __init__(self, entities, session=None): self.session = session @@ -633,44 +634,41 @@ class Query(object): @_generative() def populate_existing(self): - """Return a Query that will refresh all instances loaded. - - This includes all entities accessed from the database, including - secondary entities, eagerly-loaded collection items. - - All changes present on entities which are already present in the - session will be reset and the entities will all be marked "clean". - - An alternative to populate_existing() is to expire the Session - fully using session.expire_all(). + """Return a :class:`Query` that will expire and refresh all instances + as they are loaded, or reused from the current :class:`.Session`. + + :meth:`.populate_existing` does not improve behavior when + the ORM is used normally - the :class:`.Session` object's usual + behavior of maintaining a transaction and expiring all attributes + after rollback or commit handles object state automatically. + This method is not intended for general use. """ self._populate_existing = True def with_parent(self, instance, property=None): - """Add a join criterion corresponding to a relationship to the given - parent instance. - - instance - a persistent or detached instance which is related to class - represented by this query. - - property - string name of the property which relates this query's class to the - instance. if None, the method will attempt to find a suitable - property. - - Currently, this method only works with immediate parent relationships, - but in the future may be enhanced to work across a chain of parent - mappers. - + """Add filtering criterion that relates the given instance + to a child object or collection, using its attribute state + as well as an established :func:`.relationship()` + configuration. + + The method uses the :func:`.with_parent` function to generate + the clause, the result of which is passed to :meth:`.Query.filter`. + + Parameters are the same as :func:`.with_parent`, with the exception + that the given property can be None, in which case a search is + performed against this :class:`.Query` object's target mapper. + """ - from sqlalchemy.orm import properties - mapper = object_mapper(instance) + if property is None: + from sqlalchemy.orm import properties + mapper = object_mapper(instance) + for prop in mapper.iterate_properties: if isinstance(prop, properties.PropertyLoader) and \ prop.mapper is self._mapper_zero(): + property = prop break else: raise sa_exc.InvalidRequestError( @@ -680,11 +678,8 @@ class Query(object): self._mapper_zero().class_.__name__, instance.__class__.__name__) ) - else: - prop = mapper.get_property(property, resolve_synonyms=True) - return self.filter(prop.compare( - operators.eq, - instance, value_is_parent=True)) + + return self.filter(with_parent(instance, property)) @_generative() def add_entity(self, entity, alias=None): @@ -707,12 +702,17 @@ class Query(object): """ fromclause = self.with_labels().enable_eagerloads(False).\ + _enable_single_crit(False).\ statement.correlate(None) q = self._from_selectable(fromclause) if entities: q._set_entities(entities) return q - + + @_generative() + def _enable_single_crit(self, val): + self._enable_single_crit = val + @_generative() def _from_selectable(self, fromclause): for attr in ('_statement', '_criterion', '_order_by', '_group_by', @@ -779,8 +779,13 @@ class Query(object): def options(self, *args): """Return a new Query object, applying the given list of - MapperOptions. - + mapper options. + + Most supplied options regard changing how column- and + relationship-mapped attributes are loaded. See the sections + :ref:`deferred` and :ref:`loading_toplevel` for reference + documentation. + """ return self._options(False, *args) @@ -1937,7 +1942,8 @@ class Query(object): else: from_obj = context.froms - self._adjust_for_single_inheritance(context) + if self._enable_single_crit: + self._adjust_for_single_inheritance(context) whereclause = context.whereclause @@ -2274,7 +2280,8 @@ class Query(object): # i.e. when each _MappedEntity has its own FROM froms = context.froms - self._adjust_for_single_inheritance(context) + if self._enable_single_crit: + self._adjust_for_single_inheritance(context) if not context.primary_columns: if self._only_load_props: @@ -2406,6 +2413,7 @@ class Query(object): selected from the total results. """ + for entity, (mapper, adapter, s, i, w) in \ self._mapper_adapter_map.iteritems(): single_crit = mapper._single_table_criterion @@ -2567,8 +2575,12 @@ class _MapperEntity(_QueryEntity): ) ) - for value in self.mapper._iterate_polymorphic_properties( - self._with_polymorphic): + if self._with_polymorphic: + poly_properties = self.mapper._iterate_polymorphic_properties( + self._with_polymorphic) + else: + poly_properties = self.mapper._polymorphic_properties + for value in poly_properties: if query._only_load_props and \ value.key not in query._only_load_props: continue |