- Query.from_self() as well as query.subquery() both disable

the rendering of eager joins inside the subquery produced.
The "disable all eager joins" feature is available publically
via a new query.enable_eagerloads() generative. [ticket:1276]
- Added a rudimental series of set operations to Query that
receive Query objects as arguments, including union(),
union_all(), intersect(), except_(), insertsect_all(),
except_all().  See the API documentation for
Query.union() for examples.
- Fixed bug that prevented Query.join() and eagerloads from
attaching to a query that selected from a union or aliased union.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 48b1d0687..65cc903dd 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -3123,6 +3123,12 @@ class CompoundSelect(_SelectBaseMixin, FromClause):
     def self_group(self, against=None):
         return _FromGrouping(self)
 
+    def is_derived_from(self, fromclause):
+        for s in self.selects:
+            if s.is_derived_from(fromclause):
+                return True
+        return False
+
     def _populate_column_collection(self):
         for cols in zip(*[s.c for s in self.selects]):
             proxy = cols[0]._make_proxy(self, name=self.use_labels and cols[0]._label or None)