- merge of ticket_3499 indexed access branch

- The "hashable" flag on special datatypes such as :class:`.postgresql.ARRAY`,
:class:`.postgresql.JSON` and :class:`.postgresql.HSTORE` is now
set to False, which allows these types to be fetchable in ORM
queries that include entities within the row.  fixes #3499
- The Postgresql :class:`.postgresql.ARRAY` type now supports multidimensional
indexed access, e.g. expressions such as ``somecol[5][6]`` without
any need for explicit casts or type coercions, provided
that the :paramref:`.postgresql.ARRAY.dimensions` parameter is set to the
desired number of dimensions. fixes #3487
- The return type for the :class:`.postgresql.JSON` and :class:`.postgresql.JSONB`
when using indexed access has been fixed to work like Postgresql itself,
and returns an expression that itself is of type :class:`.postgresql.JSON`
or :class:`.postgresql.JSONB`.  Previously, the accessor would return
:class:`.NullType` which disallowed subsequent JSON-like operators to be
used. part of fixes #3503
- The :class:`.postgresql.JSON`, :class:`.postgresql.JSONB` and
:class:`.postgresql.HSTORE` datatypes now allow full control over the
return type from an indexed textual access operation, either ``column[someindex].astext``
for a JSON type or ``column[someindex]`` for an HSTORE type,
via the :paramref:`.postgresql.JSON.astext_type` and
:paramref:`.postgresql.HSTORE.text_type` parameters. also part of fixes #3503
- The :attr:`.postgresql.JSON.Comparator.astext` modifier no longer
calls upon :meth:`.ColumnElement.cast` implicitly, as PG's JSON/JSONB
types allow cross-casting between each other as well.  Code that
makes use of :meth:`.ColumnElement.cast` on JSON indexed access,
e.g. ``col[someindex].cast(Integer)``, will need to be changed
to call :attr:`.postgresql.JSON.Comparator.astext` explicitly.  This is
part of the refactor in references #3503 for consistency in operator
use.

2 files changed, 15 insertions, 13 deletions

diff --git a/lib/sqlalchemy/orm/loading.py b/lib/sqlalchemy/orm/loading.py
index b81e98a58..d8bf662fc 100644
--- a/lib/sqlalchemy/orm/loading.py
+++ b/lib/sqlalchemy/orm/loading.py
@@ -32,8 +32,7 @@ def instances(query, cursor, context):
 
     context.runid = _new_runid()
 
-    filter_fns = [ent.filter_fn for ent in query._entities]
-    filtered = id in filter_fns
+    filtered = query._has_mapper_entities
 
     single_entity = len(query._entities) == 1 and \
         query._entities[0].supports_single_entity
@@ -43,7 +42,12 @@ def instances(query, cursor, context):
             filter_fn = id
         else:
             def filter_fn(row):
-                return tuple(fn(x) for x, fn in zip(row, filter_fns))
+                return tuple(
+                    id(item)
+                    if ent.use_id_for_hash
+                    else item
+                    for ent, item in zip(query._entities, row)
+                )
 
     try:
         (process, labels) = \
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index e9b4e1982..5d08cbcd5 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -103,6 +103,7 @@ class Query(object):
     _orm_only_adapt = True
     _orm_only_from_obj_alias = True
     _current_path = _path_registry
+    _has_mapper_entities = False
 
     def __init__(self, entities, session=None):
         self.session = session
@@ -114,6 +115,7 @@ class Query(object):
             entity_wrapper = _QueryEntity
         self._entities = []
         self._primary_entity = None
+        self._has_mapper_entities = False
         for ent in util.to_list(entities):
             entity_wrapper(self, ent)
 
@@ -3191,12 +3193,14 @@ class _MapperEntity(_QueryEntity):
         if not query._primary_entity:
             query._primary_entity = self
         query._entities.append(self)
-
+        query._has_mapper_entities = True
         self.entities = [entity]
         self.expr = entity
 
     supports_single_entity = True
 
+    use_id_for_hash = True
+
     def setup_entity(self, ext_info, aliased_adapter):
         self.mapper = ext_info.mapper
         self.aliased_adapter = aliased_adapter
@@ -3242,8 +3246,6 @@ class _MapperEntity(_QueryEntity):
             self.mapper, sql_util.ColumnAdapter(
                 from_obj, self.mapper._equivalent_columns))
 
-    filter_fn = id
-
     @property
     def type(self):
         return self.mapper.class_
@@ -3472,6 +3474,8 @@ class Bundle(InspectionAttr):
 
 
 class _BundleEntity(_QueryEntity):
+    use_id_for_hash = False
+
     def __init__(self, query, bundle, setup_entities=True):
         query._entities.append(self)
         self.bundle = self.expr = bundle
@@ -3488,8 +3492,6 @@ class _BundleEntity(_QueryEntity):
 
         self.entities = ()
 
-        self.filter_fn = lambda item: item
-
         self.supports_single_entity = self.bundle.single_entity
 
     @property
@@ -3592,11 +3594,7 @@ class _ColumnEntity(_QueryEntity):
             search_entities = True
 
         self.type = type_ = column.type
-        if type_.hashable:
-            self.filter_fn = lambda item: item
-        else:
-            counter = util.counter()
-            self.filter_fn = lambda item: counter()
+        self.use_id_for_hash = not type_.hashable
 
         # If the Column is unnamed, give it a
         # label() so that mutable column expressions