- rewrote and simplified the system used to "target" columns across

selectable expressions.  On the SQL side this is represented by the
"corresponding_column()" method. This method is used heavily by the ORM
to "adapt" elements of an expression to similar, aliased expressions,
as well as to target result set columns originally bound to a
table or selectable to an aliased, "corresponding" expression.  The new
rewrite features completely consistent and accurate behavior.
- the "orig_set" and "distance" elements as well as all associated
fanfare are gone (hooray !)
- columns now have an optional "proxies" list which is a list of all
columns they are a "proxy" for; only CompoundSelect cols proxy more than one column
(just like before).  set operations are used to determine lineage.
- CompoundSelects (i.e. unions) only create one public-facing proxy column per
column name.  primary key collections come out with just one column per embedded
PK column.
- made the alias used by eager load limited subquery anonymous.

1 files changed, 2 insertions, 2 deletions

diff --git a/test/sql/selectable.py b/test/sql/selectable.py
index 9fca3ee08..aa04e2936 100755
--- a/test/sql/selectable.py
+++ b/test/sql/selectable.py
@@ -185,8 +185,8 @@ class SelectableTest(AssertMixin):
         print j4
         print j4.corresponding_column(j2.c.aid)
         print j4.c.aid
-        # TODO: this is the assertion case which fails
-#        assert j4.corresponding_column(j2.c.aid) is j4.c.aid
+        assert j4.corresponding_column(j2.c.aid) is j4.c.aid
+        assert j4.corresponding_column(a.c.id) is j4.c.id
 
 class PrimaryKeyTest(AssertMixin):
     def test_join_pk_collapse_implicit(self):