- The primary :class:`.Mapper` of a :class:`.Query` is now passed to the

:meth:`.Session.get_bind` method when calling upon
:meth:`.Query.count`, :meth:`.Query.update`, :meth:`.Query.delete`,
as well as queries against mapped columns,
:obj:`.column_property` objects, and SQL functions and expressions
derived from mapped columns.   This allows sessions that rely upon
either customized :meth:`.Session.get_bind` schemes or "bound" metadata
to work in all relevant cases.
fixes #3227 fixes #3242 fixes #1326

1 files changed, 34 insertions, 20 deletions

diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index 7302574e6..cd8b0efbe 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -146,7 +146,7 @@ class Query(object):
                         ext_info,
                         aliased_adapter
                     )
-                ent.setup_entity(*d[entity])
+                ent.setup_entity(ent, *d[entity])
 
     def _mapper_loads_polymorphically_with(self, mapper, adapter):
         for m2 in mapper._with_polymorphic_mappers or [mapper]:
@@ -160,7 +160,6 @@ class Query(object):
 
         for from_obj in obj:
             info = inspect(from_obj)
-
             if hasattr(info, 'mapper') and \
                     (info.is_mapper or info.is_aliased_class):
                 self._select_from_entity = from_obj
@@ -286,8 +285,9 @@ class Query(object):
         return self._entities[0]
 
     def _mapper_zero(self):
-        return self._select_from_entity or \
-            self._entity_zero().entity_zero
+        return self._select_from_entity \
+            if self._select_from_entity is not None \
+            else self._entity_zero().entity_zero
 
     @property
     def _mapper_entities(self):
@@ -301,11 +301,14 @@ class Query(object):
             self._mapper_zero()
         )
 
-    def _mapper_zero_or_none(self):
-        if self._primary_entity:
-            return self._primary_entity.mapper
-        else:
-            return None
+    def _bind_mapper(self):
+        ezero = self._mapper_zero()
+        if ezero is not None:
+            insp = inspect(ezero)
+            if hasattr(insp, 'mapper'):
+                return insp.mapper
+
+        return None
 
     def _only_mapper_zero(self, rationale=None):
         if len(self._entities) > 1:
@@ -988,6 +991,7 @@ class Query(object):
             statement.correlate(None)
         q = self._from_selectable(fromclause)
         q._enable_single_crit = False
+        q._select_from_entity = self._mapper_zero()
         if entities:
             q._set_entities(entities)
         return q
@@ -2526,7 +2530,7 @@ class Query(object):
 
     def _execute_and_instances(self, querycontext):
         conn = self._connection_from_session(
-            mapper=self._mapper_zero_or_none(),
+            mapper=self._bind_mapper(),
             clause=querycontext.statement,
             close_with_result=True)
 
@@ -3160,7 +3164,7 @@ class _MapperEntity(_QueryEntity):
 
     supports_single_entity = True
 
-    def setup_entity(self, ext_info, aliased_adapter):
+    def setup_entity(self, original_entity, ext_info, aliased_adapter):
         self.mapper = ext_info.mapper
         self.aliased_adapter = aliased_adapter
         self.selectable = ext_info.selectable
@@ -3507,9 +3511,9 @@ class _BundleEntity(_QueryEntity):
         for ent in self._entities:
             ent.adapt_to_selectable(c, sel)
 
-    def setup_entity(self, ext_info, aliased_adapter):
+    def setup_entity(self, original_entity, ext_info, aliased_adapter):
         for ent in self._entities:
-            ent.setup_entity(ext_info, aliased_adapter)
+            ent.setup_entity(original_entity, ext_info, aliased_adapter)
 
     def setup_context(self, query, context):
         for ent in self._entities:
@@ -3592,15 +3596,23 @@ class _ColumnEntity(_QueryEntity):
         # leaking out their entities into the main select construct
         self.actual_froms = actual_froms = set(column._from_objects)
 
-        self.entities = util.OrderedSet(
-            elem._annotations['parententity']
-            for elem in visitors.iterate(column, {})
+        all_elements = [
+            elem for elem in visitors.iterate(column, {})
             if 'parententity' in elem._annotations
-            and actual_froms.intersection(elem._from_objects)
+        ]
+
+        self.entities = util.unique_list([
+            elem._annotations['parententity']
+            for elem in all_elements
+        ])
+        self._from_entities = set(
+            elem._annotations['parententity']
+            for elem in all_elements
+            if actual_froms.intersection(elem._from_objects)
         )
 
         if self.entities:
-            self.entity_zero = list(self.entities)[0]
+            self.entity_zero = self.entities[0]
         elif self.namespace is not None:
             self.entity_zero = self.namespace
         else:
@@ -3623,10 +3635,12 @@ class _ColumnEntity(_QueryEntity):
         c.entity_zero = self.entity_zero
         c.entities = self.entities
 
-    def setup_entity(self, ext_info, aliased_adapter):
+    def setup_entity(self, original_entity, ext_info, aliased_adapter):
         if 'selectable' not in self.__dict__:
             self.selectable = ext_info.selectable
-        self.froms.add(ext_info.selectable)
+
+        if original_entity in self._from_entities:
+            self.froms.add(ext_info.selectable)
 
     def corresponds_to(self, entity):
         # TODO: just returning False here,