diff options
Diffstat (limited to 'lib/sqlalchemy')
| -rw-r--r-- | lib/sqlalchemy/orm/query.py | 65 |
1 files changed, 55 insertions, 10 deletions
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py index f86cb9085..db8d8bcbe 100644 --- a/lib/sqlalchemy/orm/query.py +++ b/lib/sqlalchemy/orm/query.py @@ -883,6 +883,9 @@ class Query(object): some_object = session.query(VersionedFoo).get((5, 10)) + some_object = session.query(VersionedFoo).get( + {"id": 5, "version_id": 10}) + :meth:`~.Query.get` is special in that it provides direct access to the identity map of the owning :class:`.Session`. If the given primary key identifier is present @@ -918,14 +921,37 @@ class Query(object): before querying the database. See :doc:`/orm/loading_relationships` for further details on relationship loading. - :param ident: A scalar or tuple value representing - the primary key. For a composite primary key, - the order of identifiers corresponds in most cases - to that of the mapped :class:`.Table` object's - primary key columns. For a :func:`.mapper` that - was given the ``primary key`` argument during - construction, the order of identifiers corresponds - to the elements present in this collection. + :param ident: A scalar, tuple, or dictionary representing the + primary key. For a composite (e.g. multiple column) primary key, + a tuple or dictionary should be passed. + + For a single-column primary key, the scalar calling form is typically + the most expedient. If the primary key of a row is the value "5", + the call looks like:: + + my_object = query.get(5) + + The tuple form contains primary key values typically in + the order in which they correspond to the mapped :class:`.Table` + object's primary key columns, or if the + :paramref:`.Mapper.primary_key` configuration parameter were used, in + the order used for that parameter. For example, if the primary key + of a row is represented by the integer + digits "5, 10" the call would look like:: + + my_object = query.get((5, 10)) + + The dictionary form should include as keys the mapped attribute names + corresponding to each element of the primary key. If the mapped class + has the attributes ``id``, ``version_id`` as the attributes which + store the object's primary key value, the call would look like:: + + my_object = query.get({"id": 5, "version_id": 10}) + + .. versionadded:: 1.3 the :meth:`.Query.get` method now optionally + accepts a dictionary of attribute names to values in order to + indicate a primary key identifier. + :return: The object instance, or ``None``. @@ -991,10 +1017,12 @@ class Query(object): if hasattr(primary_key_identity, "__composite_values__"): primary_key_identity = primary_key_identity.__composite_values__() - primary_key_identity = util.to_list(primary_key_identity) - mapper = self._only_full_mapper_zero("get") + is_dict = isinstance(primary_key_identity, dict) + if not is_dict: + primary_key_identity = util.to_list(primary_key_identity) + if len(primary_key_identity) != len(mapper.primary_key): raise sa_exc.InvalidRequestError( "Incorrect number of values in identifier to formulate " @@ -1002,6 +1030,23 @@ class Query(object): % ",".join("'%s'" % c for c in mapper.primary_key) ) + if is_dict: + try: + primary_key_identity = list( + primary_key_identity[prop.key] + for prop in mapper._identity_key_props + ) + + except KeyError: + raise sa_exc.InvalidRequestError( + "Incorrect names of values in identifier to formulate " + "primary key for query.get(); primary key attribute names" + " are %s" % ",".join( + "'%s'" % prop.key + for prop in mapper._identity_key_props + ) + ) + if ( not self._populate_existing and not mapper.always_refresh |