merged the polymorphic relationship refactoring branch in. i want to go further on that branch and introduce the foreign_keys argument, and further centralize the "intelligence" about the joins and selectables into PropertyLoader so that lazyloader/sync can be simplified, but the current branch goes pretty far.

  - relations keep track of "polymorphic_primaryjoin", "polymorphic_secondaryjoin" which it derives from the plain primaryjoin/secondaryjoin.
  - lazy/eagerloaders work from those polymorphic join objects.
  - the join exported by PropertyLoader to Query/SelectResults is the polymorphic join, so that join_to/etc work properly.
  - Query builds itself against the base Mapper again, not the "polymorphic" mapper.  uses the "polymorphic" version
 only as appropriate.  this helps join_by/join_to/etc to work with polymorphic mappers.
  - Query will also adapt incoming WHERE criterion to the polymorphic mapper, i.e. the "people" table becomes the "person_join" automatically.
  - quoting has been modified since labels made out of non-case-sensitive columns could themselves require quoting..so case_sensitive defaults to True if not otherwise specified (used to be based on the identifier itself).
  - the test harness gets an ORMTest base class and a bunch of the ORM unit tests are using it now, decreases a lot of redundancy.

1 files changed, 7 insertions, 4 deletions

diff --git a/test/testbase.py b/test/testbase.py
index 7d981509d..bc5153af0 100644
--- a/test/testbase.py
+++ b/test/testbase.py
@@ -205,6 +205,8 @@ class AssertMixin(PersistTest):
             self.assert_(db.sql_count == count, "desired statement count %d does not match %d" % (count, db.sql_count))
 
 class ORMTest(AssertMixin):
+    keep_mappers = False
+    keep_data = False
     def setUpAll(self):
         global metadata
         metadata = BoundMetaData(db)
@@ -217,10 +219,11 @@ class ORMTest(AssertMixin):
     def tearDownAll(self):
         metadata.drop_all()
     def tearDown(self):
-        clear_mappers()
-        for t in metadata.table_iterator(reverse=True):
-            t.delete().execute().close()
-
+        if not self.keep_mappers:
+            clear_mappers()
+        if not self.keep_data:
+            for t in metadata.table_iterator(reverse=True):
+                t.delete().execute().close()
 
 class EngineAssert(proxy.BaseProxyEngine):
     """decorates a SQLEngine object to match the incoming queries against a set of assertions."""