added new 'polymorphic' example. still trying to understand it :) .

fixes to relation to enable it to locate "direction" more consistently with inheritance relationships
more tweaks to parenthesizing subqueries, unions, etc.

4 files changed, 14 insertions, 9 deletions

diff --git a/lib/sqlalchemy/ansisql.py b/lib/sqlalchemy/ansisql.py
index 64715cb4f..118f9f809 100644
--- a/lib/sqlalchemy/ansisql.py
+++ b/lib/sqlalchemy/ansisql.py
@@ -240,7 +240,10 @@ class ANSICompiler(sql.Compiled):
         text = string.join([self.get_str(c) for c in cs.selects], " " + cs.keyword + " ")
         for tup in cs.clauses:
             text += " " + tup[0] + " " + self.get_str(tup[1])
-        self.strings[cs] = text
+        if cs.parens:
+            self.strings[cs] = "(" + text + ")"
+        else:
+            self.strings[cs] = text
         self.froms[cs] = "(" + text + ")"
 
     def visit_binary(self, binary):
@@ -368,7 +371,7 @@ class ANSICompiler(sql.Compiled):
                 
         text += self.visit_select_postclauses(select)
  
-        if getattr(select, 'useparens', False):
+        if getattr(select, 'parens', False):
             self.strings[select] = "(" + text + ")"
         else:
             self.strings[select] = text
diff --git a/lib/sqlalchemy/mapping/mapper.py b/lib/sqlalchemy/mapping/mapper.py
index 6a7eb9659..7b4595fb0 100644
--- a/lib/sqlalchemy/mapping/mapper.py
+++ b/lib/sqlalchemy/mapping/mapper.py
@@ -952,7 +952,6 @@ def object_mapper(object):
 
 def class_mapper(class_):
     """given a class, returns the primary Mapper associated with the class."""
-    return mapper_registry[class_]
     try:
         return mapper_registry[class_]
     except KeyError:
diff --git a/lib/sqlalchemy/mapping/properties.py b/lib/sqlalchemy/mapping/properties.py
index 023e44bf7..0f83568ed 100644
--- a/lib/sqlalchemy/mapping/properties.py
+++ b/lib/sqlalchemy/mapping/properties.py
@@ -229,7 +229,8 @@ class PropertyLoader(MapperProperty):
         
     def _get_direction(self):
         """determines our 'direction', i.e. do we represent one to many, many to many, etc."""
-#        print self.key, repr(self.parent.table.name), repr(self.parent.primarytable.name), repr(self.foreignkey.table.name)
+        #print self.key, repr(self.parent.table.name), repr(self.parent.primarytable.name), repr(self.foreignkey.table.name), repr(self.target), repr(self.foreigntable.name)
+        
         if self.parent.table is self.target:
             if self.foreignkey.primary_key:
                 return PropertyLoader.MANYTOONE
@@ -237,9 +238,9 @@ class PropertyLoader(MapperProperty):
                 return PropertyLoader.ONETOMANY
         elif self.secondaryjoin is not None:
             return PropertyLoader.MANYTOMANY
-        elif self.foreigntable == self.target:
+        elif self.foreigntable is self.target or self.foreigntable in self.mapper.tables:
             return PropertyLoader.ONETOMANY
-        elif self.foreigntable == self.parent.table:
+        elif self.foreigntable is self.parent.table or self.foreigntable in self.parent.tables:
             return PropertyLoader.MANYTOONE
         else:
             raise ArgumentError("Cant determine relation direction")
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index d4d059d6a..a6ddf8cb9 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -454,7 +454,7 @@ class CompareMixin(object):
             # assume *other is a list of selects.
             # so put them in a UNION.  if theres only one, you just get one SELECT 
             # statement out of it.
-            return self._compare('IN', union(*other))
+            return self._compare('IN', union(parens=True, *other))
     def startswith(self, other):
         return self._compare('LIKE', str(other) + "%")
     def endswith(self, other):
@@ -1123,6 +1123,7 @@ class CompoundSelect(SelectBaseMixin, FromClause):
         self.keyword = keyword
         self.selects = selects
         self.use_labels = kwargs.pop('use_labels', False)
+        self.parens = kwargs.pop('parens', False)
         self.oid_column = selects[0].oid_column
         for s in self.selects:
             s.group_by(None)
@@ -1209,7 +1210,8 @@ class Select(SelectBaseMixin, FromClause):
         def visit_compound_select(self, cs):
             self.visit_select(cs)
             for s in cs.selects:
-                s.useparens = False
+                s.parens = False
+            print "BUT", id(cs), cs.parens
         def visit_column(self, c):pass
         def visit_table(self, c):pass
         def visit_select(self, select):
@@ -1217,7 +1219,7 @@ class Select(SelectBaseMixin, FromClause):
                 return
             select.is_where = self.is_where
             select.issubquery = True
-            select.useparens = True
+            select.parens = True
             if getattr(select, '_correlated', None) is None:
                 select._correlated = self.select._froms