- A new construct :class:`.Bundle` is added, which allows for specification

of groups of column expressions to a :class:`.Query` construct.
The group of columns are returned as a single tuple by default.  The
behavior of :class:`.Bundle` can be overridden however to provide
any sort of result processing to the returned row.  One example included
is :attr:`.Composite.Comparator.bundle`, which applies a bundled form
of a "composite" mapped attribute.
[ticket:2824]
- The :func:`.composite` construct now maintains the return object
when used in a column-oriented :class:`.Query`, rather than expanding
out into individual columns.  This makes use of the new :class:`.Bundle`
feature internally.  This behavior is backwards incompatible; to
select from a composite column which will expand out, use
``MyClass.some_composite.clauses``.

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index 4a1a1823d..2f4aa5208 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -320,6 +320,9 @@ class PropComparator(operators.ColumnOperators):
     def __clause_element__(self):
         raise NotImplementedError("%r" % self)
 
+    def _query_clause_element(self):
+        return self.__clause_element__()
+
     def adapt_to_entity(self, adapt_to_entity):
         """Return a copy of this PropComparator which will use the given
         :class:`.AliasedInsp` to produce corresponding expressions.