From: Philip Jenvey <pjenvey@underboss.org>
Date: Thu, 24 Sep 2009 02:11:56 +0000 (+0000)
Subject: merge from branches/clauseelement-nonzero
X-Git-Tag: rel_0_6beta1~274
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5a9c1b8824bb84aaf8baccdfa2780a94af5c0f44;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

merge from branches/clauseelement-nonzero
adds a __nonzero__ to _BinaryExpression to avoid faulty comparisons during hash
collisions (which only occur on Jython)
fixes #1547
---

diff --git a/lib/sqlalchemy/dialects/firebird/base.py b/lib/sqlalchemy/dialects/firebird/base.py
index 71b5e5cdc7..7b0007b687 100644
--- a/lib/sqlalchemy/dialects/firebird/base.py
+++ b/lib/sqlalchemy/dialects/firebird/base.py
@@ -221,7 +221,7 @@ class FBCompiler(sql.compiler.SQLCompiler):
     visit_char_length_func = visit_length_func
 
     def function_argspec(self, func, **kw):
-        if func.clauses:
+        if func.clauses is not None and len(func.clauses):
             return self.process(func.clause_expr)
         else:
             return ""
diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index 813f42cbb8..b190af7b20 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -1075,7 +1075,7 @@ class MSDDLCompiler(compiler.DDLCompiler):
             else:
                 colspec += " NULL"
         
-        if not column.table:
+        if column.table is None:
             raise exc.InvalidRequestError("mssql requires Table-bound columns in order to generate DDL")
             
         seq_col = column.table._autoincrement_column
diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index aa616efdf3..8408e19ed0 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1300,7 +1300,7 @@ class MySQLCompiler(compiler.SQLCompiler):
         text = "UPDATE " + self.preparer.format_table(update_stmt.table) + \
                 " SET " + ', '.join(["%s=%s" % (self.preparer.format_column(c[0]), c[1]) for c in colparams])
 
-        if update_stmt._whereclause:
+        if update_stmt._whereclause is not None:
             text += " WHERE " + self.process(update_stmt._whereclause)
 
         limit = update_stmt.kwargs.get('mysql_limit', None)
diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index 454be70f89..c141515151 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -365,7 +365,7 @@ class OracleCompiler(compiler.SQLCompiler):
 
                 froms = select._get_display_froms(existingfroms)
                 whereclause = self._get_nonansi_join_whereclause(froms)
-                if whereclause:
+                if whereclause is not None:
                     select = select.where(whereclause)
                     select._oracle_visit = True
 
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index a6fa21f992..78ea1a8fc3 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -240,8 +240,8 @@ class PGCompiler(compiler.SQLCompiler):
         return text
 
     def get_select_precolumns(self, select):
-        if select._distinct:
-            if isinstance(select._distinct, bool):
+        if select._distinct is not False:
+            if select._distinct is True:
                 return "DISTINCT "
             elif isinstance(select._distinct, (list, tuple)):
                 return "DISTINCT ON (" + ', '.join(
diff --git a/lib/sqlalchemy/ext/declarative.py b/lib/sqlalchemy/ext/declarative.py
index 80faea36b2..3d8596e051 100644
--- a/lib/sqlalchemy/ext/declarative.py
+++ b/lib/sqlalchemy/ext/declarative.py
@@ -511,14 +511,14 @@ def _as_declarative(cls, classname, dict_):
     else:
         mapper_cls = mapper
 
-    if not table and 'inherits' not in mapper_args:
+    if table is None and 'inherits' not in mapper_args:
         raise exceptions.InvalidRequestError("Class %r does not have a __table__ or __tablename__ "
                     "specified and does not inherit from an existing table-mapped class." % cls)
 
     elif 'inherits' in mapper_args and not mapper_args.get('concrete', False):
         inherited_mapper = class_mapper(mapper_args['inherits'], compile=False)
         inherited_table = inherited_mapper.local_table
-        if 'inherit_condition' not in mapper_args and table:
+        if 'inherit_condition' not in mapper_args and table is not None:
             # figure out the inherit condition with relaxed rules
             # about nonexistent tables, to allow for ForeignKeys to
             # not-yet-defined tables (since we know for sure that our
@@ -527,7 +527,7 @@ def _as_declarative(cls, classname, dict_):
                 mapper_args['inherits'].__table__, table,
                 ignore_nonexistent_tables=True)
 
-        if not table:
+        if table is None:
             # single table inheritance.
             # ensure no table args
             table_args = cls.__dict__.get('__table_args__')
diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 7c4ec23f6f..3512c0b6b7 100644
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -111,7 +111,7 @@ class Mapper(object):
         self.primary_key_argument = primary_key
         self.non_primary = non_primary
 
-        if order_by:
+        if order_by is not False:
             self.order_by = util.to_list(order_by)
         else:
             self.order_by = order_by
@@ -238,10 +238,10 @@ class Mapper(object):
                 if self.concrete:
                     self.mapped_table = self.local_table
                     for mapper in self.iterate_to_root():
-                        if mapper.polymorphic_on:
+                        if mapper.polymorphic_on is not None:
                             mapper._requires_row_aliasing = True
                 else:
-                    if not self.inherit_condition:
+                    if self.inherit_condition is None:
                         # figure out inherit condition from our table to the immediate table
                         # of the inherited mapper, not its full table which could pull in other
                         # stuff we dont want (allows test/inheritance.InheritTest4 to pass)
@@ -276,11 +276,11 @@ class Mapper(object):
 
             if self.polymorphic_identity is not None:
                 self.polymorphic_map[self.polymorphic_identity] = self
-                if not self.polymorphic_on:
+                if self.polymorphic_on is None:
                     for mapper in self.iterate_to_root():
                         # try to set up polymorphic on using correesponding_column(); else leave
                         # as None
-                        if mapper.polymorphic_on:
+                        if mapper.polymorphic_on is not None:
                             self.polymorphic_on = self.mapped_table.corresponding_column(mapper.polymorphic_on)
                             break
         else:
@@ -512,9 +512,9 @@ class Mapper(object):
 
         # do a special check for the "discriminiator" column, as it may only be present
         # in the 'with_polymorphic' selectable but we need it for the base mapper
-        if self.polymorphic_on and self.polymorphic_on not in self._columntoproperty:
+        if self.polymorphic_on is not None and self.polymorphic_on not in self._columntoproperty:
             col = self.mapped_table.corresponding_column(self.polymorphic_on)
-            if not col:
+            if col is None:
                 instrument = False
                 col = self.polymorphic_on
             else:
@@ -555,14 +555,14 @@ class Mapper(object):
                 mapped_column = []
                 for c in columns:
                     mc = self.mapped_table.corresponding_column(c)
-                    if not mc:
+                    if mc is None:
                         mc = self.local_table.corresponding_column(c)
-                        if mc:
+                        if mc is not None:
                             # if the column is in the local table but not the mapped table,
                             # this corresponds to adding a column after the fact to the local table.
                             self.mapped_table._reset_exported()
                         mc = self.mapped_table.corresponding_column(c)
-                        if not mc:
+                        if mc is None:
                             raise sa_exc.ArgumentError("Column '%s' is not represented in mapper's table.  "
                                 "Use the `column_property()` function to force this column "
                                 "to be mapped as a read-only attribute." % c)
@@ -753,9 +753,15 @@ class Mapper(object):
             id(self), self.class_.__name__)
 
     def __str__(self):
-        return "Mapper|" + self.class_.__name__ + "|" + \
-                (self.local_table and self.local_table.description or str(self.local_table)) + \
-                (self.non_primary and "|non-primary" or "")
+        if self.local_table is not None:
+            tabledesc = self.local_table.description
+        else:
+            tabledesc = None
+        return "Mapper|%s|%s%s" % (
+            self.class_.__name__,
+            tabledesc,
+            self.non_primary and "|non-primary" or ""
+        )
 
     # informational / status
     
@@ -810,7 +816,7 @@ class Mapper(object):
         else:
             mappers = []
 
-        if selectable:
+        if selectable is not None:
             tables = set(sqlutil.find_tables(selectable, include_aliases=True))
             mappers = [m for m in mappers if m.local_table in tables]
 
@@ -837,7 +843,7 @@ class Mapper(object):
     def _single_table_criterion(self):
         if self.single and \
             self.inherits and \
-            self.polymorphic_on and \
+            self.polymorphic_on is not None and \
             self.polymorphic_identity is not None:
             return self.polymorphic_on.in_(
                 m.polymorphic_identity
@@ -858,7 +864,7 @@ class Mapper(object):
             return self.mapped_table
 
         spec, selectable = self.with_polymorphic
-        if selectable:
+        if selectable is not None:
             return selectable
         else:
             return self._selectable_from_mappers(self._mappers_from_spec(spec, selectable))
@@ -871,7 +877,7 @@ class Mapper(object):
                 selectable = self.with_polymorphic[1]
 
         mappers = self._mappers_from_spec(spec, selectable)
-        if selectable:
+        if selectable is not None:
             return mappers, selectable
         else:
             return mappers, self._selectable_from_mappers(mappers)
@@ -893,7 +899,7 @@ class Mapper(object):
                 chain(*[list(mapper.iterate_properties) for mapper in [self] + mappers])
             ):
                 if getattr(c, '_is_polymorphic_discriminator', False) and \
-                    (not self.polymorphic_on or c.columns[0] is not self.polymorphic_on):
+                    (self.polymorphic_on is None or c.columns[0] is not self.polymorphic_on):
                         continue
                 yield c
     
@@ -945,7 +951,7 @@ class Mapper(object):
                 else:
                     result[binary.right] = util.column_set((binary.left,))
         for mapper in self.base_mapper.polymorphic_iterator():
-            if mapper.inherit_condition:
+            if mapper.inherit_condition is not None:
                 visitors.traverse(mapper.inherit_condition, {}, {'binary':visit_binary})
 
         return result
@@ -964,11 +970,11 @@ class Mapper(object):
         # check for descriptors, either local or from
         # an inherited class
         if local:
-            if self.class_.__dict__.get(assigned_name, None)\
+            if self.class_.__dict__.get(assigned_name, None) is not None\
                 and self._is_userland_descriptor(self.class_.__dict__[assigned_name]):
                 return True
         else:
-            if getattr(self.class_, assigned_name, None)\
+            if getattr(self.class_, assigned_name, None) is not None\
                 and self._is_userland_descriptor(getattr(self.class_, assigned_name)):
                 return True
 
@@ -991,7 +997,7 @@ class Mapper(object):
 
     def _canload(self, state, allow_subtypes):
         s = self.primary_mapper()
-        if self.polymorphic_on or allow_subtypes:
+        if self.polymorphic_on is not None or allow_subtypes:
             return _state_mapper(state).isa(s)
         else:
             return _state_mapper(state) is s
@@ -1319,7 +1325,7 @@ class Mapper(object):
                     for col in mapper._cols_by_table[table]:
                         if col is mapper.version_id_col:
                             params[col.key] = 1
-                        elif mapper.polymorphic_on and mapper.polymorphic_on.shares_lineage(col):
+                        elif mapper.polymorphic_on is not None and mapper.polymorphic_on.shares_lineage(col):
                             if self._should_log_debug:
                                 self._log_debug(
                                     "Using polymorphic identity '%s' for insert column '%s'" %
@@ -1352,7 +1358,7 @@ class Mapper(object):
                                 history = attributes.get_state_history(state, prop.key, passive=True)
                                 if history.added:
                                     hasdata = True
-                        elif mapper.polymorphic_on and mapper.polymorphic_on.shares_lineage(col) and col not in pks:
+                        elif mapper.polymorphic_on is not None and mapper.polymorphic_on.shares_lineage(col) and col not in pks:
                             pass
                         else:
                             if post_update_cols is not None and col not in post_update_cols:
@@ -1391,7 +1397,7 @@ class Mapper(object):
                 for col in mapper._pks_by_table[table]:
                     clause.clauses.append(col == sql.bindparam(col._label, type_=col.type))
 
-                if mapper.version_id_col and table.c.contains_column(mapper.version_id_col):
+                if mapper.version_id_col is not None and table.c.contains_column(mapper.version_id_col):
                     clause.clauses.append(mapper.version_id_col == sql.bindparam(mapper.version_id_col._label, type_=col.type))
 
                 statement = table.update(clause)
@@ -1460,12 +1466,12 @@ class Mapper(object):
         postfetch_cols = resultproxy.postfetch_cols()
         generated_cols = list(resultproxy.prefetch_cols())
 
-        if self.polymorphic_on:
+        if self.polymorphic_on is not None:
             po = table.corresponding_column(self.polymorphic_on)
-            if po:
+            if po is not None:
                 generated_cols.append(po)
 
-        if self.version_id_col:
+        if self.version_id_col is not None:
             generated_cols.append(self.version_id_col)
 
         for c in generated_cols:
@@ -1513,7 +1519,7 @@ class Mapper(object):
                     delete.setdefault(connection, []).append(params)
                 for col in mapper._pks_by_table[table]:
                     params[col.key] = mapper._get_state_attr_by_column(state, col)
-                if mapper.version_id_col and table.c.contains_column(mapper.version_id_col):
+                if mapper.version_id_col is not None and table.c.contains_column(mapper.version_id_col):
                     params[mapper.version_id_col.key] = mapper._get_state_attr_by_column(state, mapper.version_id_col)
 
             for connection, del_objects in delete.iteritems():
@@ -1521,7 +1527,7 @@ class Mapper(object):
                 clause = sql.and_()
                 for col in mapper._pks_by_table[table]:
                     clause.clauses.append(col == sql.bindparam(col.key, type_=col.type))
-                if mapper.version_id_col and table.c.contains_column(mapper.version_id_col):
+                if mapper.version_id_col is not None and table.c.contains_column(mapper.version_id_col):
                     clause.clauses.append(
                         mapper.version_id_col == 
                         sql.bindparam(mapper.version_id_col.key, type_=mapper.version_id_col.type))
@@ -1560,16 +1566,19 @@ class Mapper(object):
         if polymorphic_from or refresh_state:
             polymorphic_on = None
         else:
-            polymorphic_on = polymorphic_discriminator or self.polymorphic_on
+            if polymorphic_discriminator is not None:
+                polymorphic_on = polymorphic_discriminator
+            else:
+                polymorphic_on = self.polymorphic_on
             polymorphic_instances = util.PopulateDict(self._configure_subclass_mapper(context, path, adapter))
 
         version_id_col = self.version_id_col
 
         if adapter:
             pk_cols = [adapter.columns[c] for c in pk_cols]
-            if polymorphic_on:
+            if polymorphic_on is not None:
                 polymorphic_on = adapter.columns[polymorphic_on]
-            if version_id_col:
+            if version_id_col is not None:
                 version_id_col = adapter.columns[version_id_col]
 
         identity_class = self._identity_class
@@ -1623,7 +1632,7 @@ class Mapper(object):
                 if ret is not EXT_CONTINUE:
                     row = ret
 
-            if polymorphic_on:
+            if polymorphic_on is not None:
                 discriminator = row[polymorphic_on]
                 if discriminator is not None:
                     _instance = polymorphic_instances[discriminator]
@@ -1654,7 +1663,7 @@ class Mapper(object):
                 currentload = not isnew
                 loaded_instance = False
 
-                if not currentload and version_id_col and context.version_check and \
+                if not currentload and version_id_col is not None and context.version_check and \
                         self._get_state_attr_by_column(state, self.version_id_col) != row[version_id_col]:
                     raise exc.ConcurrentModificationError(
                             "Instance '%s' version of %s does not match %s" 
@@ -1856,7 +1865,7 @@ def _load_scalar_attributes(state, attribute_names):
     result = False
     if mapper.inherits and not mapper.concrete:
         statement = mapper._optimized_get_statement(state, attribute_names)
-        if statement:
+        if statement is not None:
             result = session.query(mapper).from_statement(statement)._get(None, only_load_props=attribute_names, refresh_state=state)
 
     if result is False:
diff --git a/lib/sqlalchemy/orm/properties.py b/lib/sqlalchemy/orm/properties.py
index 739b2c5194..445496e34a 100644
--- a/lib/sqlalchemy/orm/properties.py
+++ b/lib/sqlalchemy/orm/properties.py
@@ -499,7 +499,7 @@ class RelationProperty(StrategizedProperty):
                     to_selectable = to_selectable.alias()
 
                 single_crit = target_mapper._single_table_criterion
-                if single_crit:
+                if single_crit is not None:
                     if criterion is not None:
                         criterion = single_crit & criterion
                     else:
@@ -525,19 +525,19 @@ class RelationProperty(StrategizedProperty):
             # annotate the *local* side of the join condition, in the case of pj + sj this
             # is the full primaryjoin, in the case of just pj its the local side of
             # the primaryjoin.  
-            if sj:
+            if sj is not None:
                 j = _orm_annotate(pj) & sj
             else:
                 j = _orm_annotate(pj, exclude=self.property.remote_side)
             
-            if criterion and target_adapter:
+            if criterion is not None and target_adapter:
                 # limit this adapter to annotated only?
                 criterion = target_adapter.traverse(criterion)
 
             # only have the "joined left side" of what we return be subject to Query adaption.  The right
             # side of it is used for an exists() subquery and should not correlate or otherwise reach out
             # to anything in the enclosing query.
-            if criterion:
+            if criterion is not None:
                 criterion = criterion._annotate({'_halt_adapt': True})
             
             crit = j & criterion
@@ -560,7 +560,7 @@ class RelationProperty(StrategizedProperty):
                 raise sa_exc.InvalidRequestError("'contains' not implemented for scalar attributes.  Use ==")
             clause = self.property._optimized_compare(other, adapt_source=self.adapter)
 
-            if self.property.secondaryjoin:
+            if self.property.secondaryjoin is not None:
                 clause.negation_clause = self.__negated_contains_or_equals(other)
 
             return clause
@@ -747,7 +747,7 @@ class RelationProperty(StrategizedProperty):
                 util.assert_arg_type(val, sql.ClauseElement, attr)
                 setattr(self, attr, _orm_deannotate(val))
         
-        if self.order_by:
+        if self.order_by is not False and self.order_by is not None:
             self.order_by = [expression._literal_as_column(x) for x in util.to_list(self.order_by)]
         
         self._foreign_keys = util.column_set(expression._literal_as_column(x) for x in util.to_column_set(self._foreign_keys))
@@ -858,7 +858,7 @@ class RelationProperty(StrategizedProperty):
 
             self.synchronize_pairs = eq_pairs
 
-        if self.secondaryjoin:
+        if self.secondaryjoin is not None:
             sq_pairs = criterion_as_pairs(self.secondaryjoin, consider_as_foreign_keys=self._foreign_keys, any_operator=self.viewonly)
             sq_pairs = [(l, r) for l, r in sq_pairs if (self._col_is_part_of_mappings(l) and self._col_is_part_of_mappings(r)) or r in self._foreign_keys]
 
@@ -968,11 +968,11 @@ class RelationProperty(StrategizedProperty):
             else:
                 if self.viewonly:
                     eq_pairs = self.synchronize_pairs
-                    if self.secondaryjoin:
+                    if self.secondaryjoin is not None:
                         eq_pairs += self.secondary_synchronize_pairs
                 else:
                     eq_pairs = criterion_as_pairs(self.primaryjoin, consider_as_foreign_keys=self._foreign_keys, any_operator=True)
-                    if self.secondaryjoin:
+                    if self.secondaryjoin is not None:
                         eq_pairs += criterion_as_pairs(self.secondaryjoin, consider_as_foreign_keys=self._foreign_keys, any_operator=True)
                     eq_pairs = [(l, r) for l, r in eq_pairs if self._col_is_part_of_mappings(l) and self._col_is_part_of_mappings(r)]
 
@@ -1061,7 +1061,7 @@ class RelationProperty(StrategizedProperty):
         else:
             aliased = True
 
-        aliased = aliased or bool(source_selectable)
+        aliased = aliased or (source_selectable is not None)
 
         primaryjoin, secondaryjoin, secondary = self.primaryjoin, self.secondaryjoin, self.secondary
         
@@ -1073,32 +1073,32 @@ class RelationProperty(StrategizedProperty):
         dest_mapper = of_type or self.mapper
         
         single_crit = dest_mapper._single_table_criterion
-        if single_crit:
-            if secondaryjoin:
+        if single_crit is not None:
+            if secondaryjoin is not None:
                 secondaryjoin = secondaryjoin & single_crit
             else:
                 primaryjoin = primaryjoin & single_crit
             
 
         if aliased:
-            if secondary:
+            if secondary is not None:
                 secondary = secondary.alias()
                 primary_aliasizer = ClauseAdapter(secondary)
-                if dest_selectable:
+                if dest_selectable is not None:
                     secondary_aliasizer = ClauseAdapter(dest_selectable, equivalents=self.mapper._equivalent_columns).chain(primary_aliasizer)
                 else:
                     secondary_aliasizer = primary_aliasizer
 
-                if source_selectable:
+                if source_selectable is not None:
                     primary_aliasizer = ClauseAdapter(secondary).chain(ClauseAdapter(source_selectable, equivalents=self.parent._equivalent_columns))
 
                 secondaryjoin = secondary_aliasizer.traverse(secondaryjoin)
             else:
-                if dest_selectable:
+                if dest_selectable is not None:
                     primary_aliasizer = ClauseAdapter(dest_selectable, exclude=self.local_side, equivalents=self.mapper._equivalent_columns)
-                    if source_selectable:
+                    if source_selectable is not None:
                         primary_aliasizer.chain(ClauseAdapter(source_selectable, exclude=self.remote_side, equivalents=self.parent._equivalent_columns))
-                elif source_selectable:
+                elif source_selectable is not None:
                     primary_aliasizer = ClauseAdapter(source_selectable, exclude=self.remote_side, equivalents=self.parent._equivalent_columns)
 
                 secondary_aliasizer = None
@@ -1109,9 +1109,15 @@ class RelationProperty(StrategizedProperty):
         else:
             target_adapter = None
 
+        if source_selectable is None:
+            source_selectable = self.parent.local_table
+            
+        if dest_selectable is None:
+            dest_selectable = self.mapper.local_table
+            
         return (primaryjoin, secondaryjoin, 
-                (source_selectable or self.parent.local_table), 
-                (dest_selectable or self.mapper.local_table), secondary, target_adapter)
+                source_selectable, 
+                dest_selectable, secondary, target_adapter)
 
     def _get_join(self, parent, primary=True, secondary=True, polymorphic_parent=True):
         """deprecated.  use primary_join_against(), secondary_join_against(), full_join_against()"""
@@ -1162,7 +1168,7 @@ class BackRef(object):
 
         mapper = prop.mapper.primary_mapper()
         if mapper._get_property(self.key, raiseerr=False) is None:
-            if prop.secondary:
+            if prop.secondary is not None:
                 pj = self.kwargs.pop('primaryjoin', prop.secondaryjoin)
                 sj = self.kwargs.pop('secondaryjoin', prop.primaryjoin)
             else:
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index 987390e870..2ffa677cb7 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -167,7 +167,7 @@ class Query(object):
         else:
             search = None
 
-        if search:
+        if search is not None:
             alias = self._polymorphic_adapters.get(search, None)
             if alias:
                 return alias.adapt_clause(element)
@@ -179,7 +179,7 @@ class Query(object):
 
             for adapter in adapters:
                 e = adapter(elem)
-                if e:
+                if e is not None:
                     return e
         return replace
 
@@ -191,7 +191,7 @@ class Query(object):
             if "_orm_adapt" in elem._annotations or "parententity" in elem._annotations:
                 for adapter in adapters:
                     e = adapter(elem)
-                    if e:
+                    if e is not None:
                         return e
         return replace
 
@@ -284,7 +284,7 @@ class Query(object):
     def _no_criterion_condition(self, meth):
         if not self._enable_assertions:
             return
-        if self._criterion or self._statement or self._from_obj or \
+        if self._criterion is not None or self._statement is not None or self._from_obj or \
                 self._limit is not None or self._offset is not None or \
                 self._group_by:
             raise sa_exc.InvalidRequestError("Query.%s() being called on a Query with existing criterion. " % meth)
@@ -606,7 +606,7 @@ class Query(object):
     def add_entity(self, entity, alias=None):
         """add a mapped entity to the list of result columns to be returned."""
 
-        if alias:
+        if alias is not None:
             entity = aliased(entity, alias)
 
         self._entities = list(self._entities)
@@ -992,7 +992,7 @@ class Query(object):
                 onclause = descriptor
 
             if isinstance(onclause, interfaces.PropComparator):
-                if not right_entity:
+                if right_entity is None:
                     right_entity = onclause.property.mapper
                     of_type = getattr(onclause, '_of_type', None)
                     if of_type:
@@ -1115,7 +1115,7 @@ class Query(object):
 
         if self._from_obj:
             replace_clause_index, clause = sql_util.find_join_source(self._from_obj, left_selectable)
-            if clause:
+            if clause is not None:
                 # the entire query's FROM clause is an alias of itself (i.e. from_self(), similar).
                 # if the left clause is that one, ensure it aliases to the left side.
                 if self._from_obj_alias and clause is self._from_obj[0]:
@@ -1268,7 +1268,7 @@ class Query(object):
         This results in an execution of the underlying query.
 
         """
-        if self._statement:
+        if self._statement is not None:
             ret = list(self)[0:1]
         else:
             ret = list(self[0:1])
@@ -1485,7 +1485,7 @@ class Query(object):
             'offset':self._offset,
             'distinct':self._distinct,
             'group_by':self._group_by or None,
-            'having':self._having or None
+            'having':self._having
         }
 
     @property
@@ -1619,7 +1619,11 @@ class Query(object):
         if synchronize_session == 'evaluate':
             try:
                 evaluator_compiler = evaluator.EvaluatorCompiler()
-                eval_condition = evaluator_compiler.process(self.whereclause or expression._Null)
+                if self.whereclause is not None:
+                    eval_condition = evaluator_compiler.process(self.whereclause)
+                else:
+                    eval_condition = evaluator_compiler.process(expression._Null)
+                    
             except evaluator.UnevaluatableError:
                 raise sa_exc.InvalidRequestError("Could not evaluate current criteria in Python.  "
                         "Specify 'fetch' or False for the synchronize_session parameter.")
@@ -1719,7 +1723,11 @@ class Query(object):
         if synchronize_session == 'evaluate':
             try:
                 evaluator_compiler = evaluator.EvaluatorCompiler()
-                eval_condition = evaluator_compiler.process(self.whereclause or expression._Null)
+                if self.whereclause is not None:
+                    eval_condition = evaluator_compiler.process(self.whereclause)
+                else:
+                    eval_condition = evaluator_compiler.process(expression._Null)
+                    
 
                 value_evaluators = {}
                 for key,value in values.iteritems():
@@ -1774,7 +1782,7 @@ class Query(object):
     def _compile_context(self, labels=True):
         context = QueryContext(self)
 
-        if context.statement:
+        if context.statement is not None:
             return context
 
         if self._lockmode:
@@ -1892,7 +1900,7 @@ class Query(object):
         """
         for entity, (mapper, adapter, s, i, w) in self._mapper_adapter_map.iteritems():
             single_crit = mapper._single_table_criterion
-            if single_crit:
+            if single_crit is not None:
                 if adapter:
                     single_crit = adapter.traverse(single_crit)
                 single_crit = self._adapt_clause(single_crit, False, False)
@@ -2043,7 +2051,7 @@ class _MapperEntity(_QueryEntity):
                 column_collection=context.primary_columns
             )
 
-        if self._polymorphic_discriminator:
+        if self._polymorphic_discriminator is not None:
             if adapter:
                 pd = adapter.columns[self._polymorphic_discriminator]
             else:
@@ -2151,7 +2159,7 @@ log.class_logger(Query)
 class QueryContext(object):
     def __init__(self, query):
 
-        if query._statement:
+        if query._statement is not None:
             if isinstance(query._statement, expression._SelectBaseMixin) and not query._statement.use_labels:
                 self.statement = query._statement.apply_labels()
             else:
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 002ccd5098..760dfe81fc 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -865,7 +865,7 @@ class Session(object):
                     return self.__binds[c_mapper.base_mapper]
                 elif c_mapper.mapped_table in self.__binds:
                     return self.__binds[c_mapper.mapped_table]
-            if clause:
+            if clause is not None:
                 for t in sql_util.find_tables(clause):
                     if t in self.__binds:
                         return self.__binds[t]
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index 4ab1a49486..e9d2c399c0 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -378,6 +378,7 @@ class LazyLoader(AbstractRelationLoader):
                             use_proxies=True, 
                             equivalents=self.mapper._equivalent_columns
                         )
+                        
         if self.use_get:
             for col in self._equated_columns.keys():
                 if col in self.mapper._equivalent_columns:
@@ -419,7 +420,7 @@ class LazyLoader(AbstractRelationLoader):
                 o = state.obj() # strong ref
                 bindparam.value = lambda: mapper._get_committed_attr_by_column(o, bind_to_col[bindparam.key])
 
-        if self.parent_property.secondary and alias_secondary:
+        if self.parent_property.secondary is not None and alias_secondary:
             criterion = sql_util.ClauseAdapter(self.parent_property.secondary.alias()).traverse(criterion)
 
         criterion = visitors.cloned_traverse(criterion, {}, {'bindparam':visit_bindparam})
@@ -497,7 +498,7 @@ class LazyLoader(AbstractRelationLoader):
         lookup = util.column_dict()
         equated_columns = util.column_dict()
 
-        if reverse_direction and not prop.secondaryjoin:
+        if reverse_direction and prop.secondaryjoin is None:
             for l, r in prop.local_remote_pairs:
                 _list = lookup.setdefault(r, [])
                 _list.append((r, l))
@@ -520,7 +521,7 @@ class LazyLoader(AbstractRelationLoader):
         
         lazywhere = prop.primaryjoin
 
-        if not prop.secondaryjoin or not reverse_direction:
+        if prop.secondaryjoin is None or not reverse_direction:
             lazywhere = visitors.replacement_traverse(lazywhere, {}, col_to_bind) 
         
         if prop.secondaryjoin is not None:
@@ -685,7 +686,7 @@ class EagerLoader(AbstractRelationLoader):
             entity_key, default_towrap = entity, entity.selectable
         else:
             index, clause = sql_util.find_join_source(context.from_clause, entity.selectable)
-            if clause:
+            if clause is not None:
                 # join to an existing FROM clause on the query.
                 # key it to its list index in the eager_joins dict.
                 # Query._compile_context will adapt as needed and append to the
@@ -721,7 +722,7 @@ class EagerLoader(AbstractRelationLoader):
         # send a hint to the Query as to where it may "splice" this join
         eagerjoin.stop_on = entity.selectable
         
-        if not self.parent_property.secondary and context.query._should_nest_selectable and not parentmapper:
+        if self.parent_property.secondary is None and context.query._should_nest_selectable and not parentmapper:
             # for parentclause that is the non-eager end of the join,
             # ensure all the parent cols in the primaryjoin are actually in the
             # columns clause (i.e. are not deferred), so that aliasing applied by the Query propagates 
@@ -840,7 +841,7 @@ class EagerLazyOption(StrategizedOption):
 class LoadEagerFromAliasOption(PropertyOption):
     def __init__(self, key, alias=None):
         super(LoadEagerFromAliasOption, self).__init__(key)
-        if alias:
+        if alias is not None:
             if not isinstance(alias, basestring):
                 m, alias, is_aliased_class = mapperutil._entity_info(alias)
         self.alias = alias
@@ -850,7 +851,7 @@ class LoadEagerFromAliasOption(PropertyOption):
         pass
         
     def process_query_property(self, query, paths, mappers):
-        if self.alias:
+        if self.alias is not None:
             if isinstance(self.alias, basestring):
                 mapper = mappers[-1]
                 (root_mapper, propname) = paths[-1][-2:]
diff --git a/lib/sqlalchemy/orm/util.py b/lib/sqlalchemy/orm/util.py
index f10f5a0d4c..168131df0c 100644
--- a/lib/sqlalchemy/orm/util.py
+++ b/lib/sqlalchemy/orm/util.py
@@ -288,7 +288,8 @@ class AliasedClass(object):
     def __init__(self, cls, alias=None, name=None):
         self.__mapper = _class_to_mapper(cls)
         self.__target = self.__mapper.class_
-        alias = alias or self.__mapper._with_polymorphic_selectable.alias()
+        if alias is None:
+            alias = self.__mapper._with_polymorphic_selectable.alias()
         self.__adapter = sql_util.ClauseAdapter(alias, equivalents=self.__mapper._equivalent_columns)
         self.__alias = alias
         # used to assign a name to the RowTuple object
@@ -390,7 +391,7 @@ class _ORMJoin(expression.Join):
             if isinstance(onclause, basestring):
                 prop = left_mapper.get_property(onclause)
             elif isinstance(onclause, attributes.QueryableAttribute):
-                if not adapt_from:
+                if adapt_from is None:
                     adapt_from = onclause.__clause_element__()
                 prop = onclause.property
             elif isinstance(onclause, MapperProperty):
@@ -406,7 +407,7 @@ class _ORMJoin(expression.Join):
                                 dest_polymorphic=True,
                                 of_type=right_mapper)
 
-                if sj:
+                if sj is not None:
                     left = sql.join(left, secondary, pj, isouter)
                     onclause = sj
                 else:
diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py
index 9305c4b197..dc212ccac3 100644
--- a/lib/sqlalchemy/schema.py
+++ b/lib/sqlalchemy/schema.py
@@ -710,7 +710,7 @@ class Column(SchemaItem, expression.ColumnClause):
             [repr(self.name)] + [repr(self.type)] +
             [repr(x) for x in self.foreign_keys if x is not None] +
             [repr(x) for x in self.constraints] +
-            [(self.table and "table=<%s>" % self.table.description or "")] +
+            [(self.table is not None and "table=<%s>" % self.table.description or "")] +
             ["%s=%s" % (k, repr(getattr(self, k))) for k in kwarg])
 
     def _set_parent(self, table):
@@ -764,7 +764,7 @@ class Column(SchemaItem, expression.ColumnClause):
         del self._table_events
     
     def _on_table_attach(self, fn):
-        if self.table:
+        if self.table is not None:
             fn(self.table)
         else:
             self._table_events.add(fn)
@@ -1001,7 +1001,7 @@ class ForeignKey(SchemaItem):
                 key = colname
                 _column = table.c.get(colname, None)
 
-            if not _column:
+            if _column is None:
                 raise exc.NoReferencedColumnError(
                     "Could not create ForeignKey '%s' on table '%s': "
                     "table '%s' has no column named '%s'" % (
@@ -1061,7 +1061,7 @@ class DefaultGenerator(SchemaItem):
     @property
     def bind(self):
         """Return the connectable associated with this default."""
-        if getattr(self, 'column', None):
+        if getattr(self, 'column', None) is not None:
             return self.column.table.bind
         else:
             return None
@@ -1345,7 +1345,7 @@ class CheckConstraint(Constraint):
             raise exc.ArgumentError(
                 "sqltext must be a string and will be used verbatim.")
         self.sqltext = sqltext
-        if table:
+        if table is not None:
             self._set_parent(table)
             
     def __visit_name__(self):
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 7bd0c1b05d..b4b901067b 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -368,11 +368,11 @@ class SQLCompiler(engine.Compiled):
 
     def visit_case(self, clause, **kwargs):
         x = "CASE "
-        if clause.value:
+        if clause.value is not None:
             x += self.process(clause.value) + " "
         for cond, result in clause.whens:
             x += "WHEN " + self.process(cond) + " THEN " + self.process(result) + " "
-        if clause.else_:
+        if clause.else_ is not None:
             x += "ELSE " + self.process(clause.else_) + " "
         x += "END"
         return x
@@ -538,7 +538,7 @@ class SQLCompiler(engine.Compiled):
         if isinstance(column, sql._Label):
             return column
 
-        if select and select.use_labels and column._label:
+        if select is not None and select.use_labels and column._label:
             return _CompileLabel(column, column._label)
 
         if \
@@ -741,7 +741,7 @@ class SQLCompiler(engine.Compiled):
             if self.returning_precedes_values:
                 text += " " + self.returning_clause(update_stmt, update_stmt._returning)
                 
-        if update_stmt._whereclause:
+        if update_stmt._whereclause is not None:
             text += " WHERE " + self.process(update_stmt._whereclause)
 
         if self.returning and not self.returning_precedes_values:
@@ -891,7 +891,7 @@ class SQLCompiler(engine.Compiled):
             if self.returning_precedes_values:
                 text += " " + self.returning_clause(delete_stmt, delete_stmt._returning)
                 
-        if delete_stmt._whereclause:
+        if delete_stmt._whereclause is not None:
             text += " WHERE " + self.process(delete_stmt._whereclause)
 
         if self.returning and not self.returning_precedes_values:
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 1b9ae6e8fa..0ece67e20f 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -974,7 +974,7 @@ def _no_literals(element):
 def _corresponding_column_or_error(fromclause, column, require_embedded=False):
     c = fromclause.corresponding_column(column,
             require_embedded=require_embedded)
-    if not c:
+    if c is None:
         raise exc.InvalidRequestError(
                 "Given column '%s', attached to table '%s', "
                 "failed to locate a corresponding column from table '%s'"
@@ -1044,7 +1044,18 @@ class ClauseElement(Visitable):
         d = self.__dict__.copy()
         d.pop('_is_clone_of', None)
         return d
-
+    
+    if util.jython:
+         def __hash__(self):
+             """Return a distinct hash code.
+
+             ClauseElements may have special equality comparisons which
+             makes us rely on them having unique hash codes for use in
+             hash-based collections. Stock __hash__ doesn't guarantee
+             unique values on platforms with moving GCs.
+             """
+             return id(self)
+        
     def _annotate(self, values):
         """return a copy of this ClauseElement with the given annotations
         dictionary.
@@ -1264,16 +1275,8 @@ class ClauseElement(Visitable):
     def __invert__(self):
         return self._negate()
 
-    if util.jython:
-        def __hash__(self):
-            """Return a distinct hash code.
-
-            ClauseElements may have special equality comparisons which
-            makes us rely on them having unique hash codes for use in
-            hash-based collections. Stock __hash__ doesn't guarantee
-            unique values on platforms with moving GCs.
-            """
-            return id(self)
+    def __nonzero__(self):
+       raise TypeError("Boolean value of this clause is not defined")
 
     def _negate(self):
         if hasattr(self, 'negation_clause'):
@@ -1797,10 +1800,9 @@ class ColumnCollection(util.OrderedProperties):
             # column names in their exported columns collection
             existing = self[key]
             if not existing.shares_lineage(value):
-                table = getattr(existing, 'table', None) and existing.table.description
                 util.warn(("Column %r on table %r being replaced by another "
                            "column with the same key.  Consider use_labels "
-                           "for select() statements.")  % (key, table))
+                           "for select() statements.")  % (key, getattr(existing, 'table', None)))
         util.OrderedProperties.__setitem__(self, key, value)
 
     def remove(self, column):
@@ -2343,7 +2345,7 @@ class _Case(ColumnElement):
         except TypeError:
             pass
 
-        if value:
+        if value is not None:
             whenlist = [
                 (_literal_as_binds(c).self_group(), _literal_as_binds(r)) for (c, r) in whens
             ]
@@ -2370,19 +2372,19 @@ class _Case(ColumnElement):
             self.else_ = None
 
     def _copy_internals(self, clone=_clone):
-        if self.value:
+        if self.value is not None:
             self.value = clone(self.value)
         self.whens = [(clone(x), clone(y)) for x, y in self.whens]
-        if self.else_:
+        if self.else_ is not None:
             self.else_ = clone(self.else_)
 
     def get_children(self, **kwargs):
-        if self.value:
+        if self.value is not None:
             yield self.value
         for x, y in self.whens:
             yield x
             yield y
-        if self.else_:
+        if self.else_ is not None:
             yield self.else_ 
 
     @property
@@ -2548,7 +2550,13 @@ class _BinaryExpression(ColumnElement):
             self.modifiers = {}
         else:
             self.modifiers = modifiers
-
+    
+    def __nonzero__(self):
+        try:
+            return self.operator(hash(self.left), hash(self.right))
+        except:
+            raise TypeError("Boolean value of this clause is not defined")
+        
     @property
     def _from_objects(self):
         return self.left._from_objects + self.right._from_objects
@@ -3017,7 +3025,7 @@ class ColumnClause(_Immutable, ColumnElement):
         if self.is_literal:
             return None
 
-        elif self.table and self.table.named_with_column:
+        elif self.table is not None and self.table.named_with_column:
             if getattr(self.table, 'schema', None):
                 label = self.table.schema + "_" + \
                             _escape_for_generated(self.table.name) + "_" + \
@@ -3047,7 +3055,7 @@ class ColumnClause(_Immutable, ColumnElement):
 
     @property
     def _from_objects(self):
-        if self.table:
+        if self.table is not None:
             return [self.table]
         else:
             return []
@@ -3264,7 +3272,7 @@ class _SelectBaseMixin(object):
         if len(clauses) == 1 and clauses[0] is None:
             self._order_by_clause = ClauseList()
         else:
-            if getattr(self, '_order_by_clause', None):
+            if getattr(self, '_order_by_clause', None) is not None:
                 clauses = list(self._order_by_clause) + list(clauses)
             self._order_by_clause = ClauseList(*clauses)
 
@@ -3277,7 +3285,7 @@ class _SelectBaseMixin(object):
         if len(clauses) == 1 and clauses[0] is None:
             self._group_by_clause = ClauseList()
         else:
-            if getattr(self, '_group_by_clause', None):
+            if getattr(self, '_group_by_clause', None) is not None:
                 clauses = list(self._group_by_clause) + list(clauses)
             self._group_by_clause = ClauseList(*clauses)
 
@@ -3433,28 +3441,31 @@ class Select(_SelectBaseMixin, FromClause):
         self._froms = util.OrderedSet()
 
         if columns:
-            self._raw_columns = [
-                isinstance(c, _ScalarSelect) and 
-                c.self_group(against=operators.comma_op) or c
-                for c in [_literal_as_column(c) for c in columns]
-            ]
+            self._raw_columns = []
+            for c in columns:
+                c = _literal_as_column(c)
+                if isinstance(c, _ScalarSelect):
+                    c = c.self_group(against=operators.comma_op)
+                self._raw_columns.append(c)
 
             self._froms.update(_from_objects(*self._raw_columns))
         else:
             self._raw_columns = []
 
-        if whereclause:
+        if whereclause is not None:
             self._whereclause = _literal_as_text(whereclause)
             self._froms.update(_from_objects(self._whereclause))
         else:
             self._whereclause = None
 
-        if from_obj:
-            self._froms.update(
-                _is_literal(f) and _TextClause(f) or f
-                for f in util.to_list(from_obj))
+        if from_obj is not None:
+            for f in util.to_list(from_obj):
+                if _is_literal(f):
+                    self._froms.add(_TextClause(f))
+                else:
+                    self._froms.add(f)
 
-        if having:
+        if having is not None:
             self._having = _literal_as_text(having)
         else:
             self._having = None
@@ -3977,7 +3988,7 @@ class Update(_ValuesBase):
         _ValuesBase.__init__(self, table, values)
         self._bind = bind
         self._returning = returning
-        if whereclause:
+        if whereclause is not None:
             self._whereclause = _literal_as_text(whereclause)
         else:
             self._whereclause = None
@@ -4027,7 +4038,7 @@ class Delete(_UpdateBase):
         self.table = table
         self._returning = returning
         
-        if whereclause:
+        if whereclause is not None:
             self._whereclause = _literal_as_text(whereclause)
         else:
             self._whereclause = None
diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py
index 9be405e219..02165aad5e 100644
--- a/lib/sqlalchemy/sql/util.py
+++ b/lib/sqlalchemy/sql/util.py
@@ -103,7 +103,7 @@ def join_condition(a, b, ignore_nonexistent_tables=False):
             else:
                 raise
                 
-        if col:
+        if col is not None:
             crit.append(col == fk.parent)
             constraints.add(fk.constraint)
     if a is not b:
@@ -116,7 +116,7 @@ def join_condition(a, b, ignore_nonexistent_tables=False):
                 else:
                     raise
 
-            if col:
+            if col is not None:
                 crit.append(col == fk.parent)
                 constraints.add(fk.constraint)
 
@@ -267,9 +267,9 @@ def splice_joins(left, right, stop_on=None):
             stack.append((right.left, right))
         else:
             right = adapter.traverse(right)
-        if prevright:
+        if prevright is not None:
             prevright.left = right
-        if not ret:
+        if ret is None:
             ret = right
 
     return ret
@@ -467,10 +467,10 @@ class ClauseAdapter(visitors.ReplacingCloningVisitor):
     def _corresponding_column(self, col, require_embedded, _seen=util.EMPTY_SET):
         newcol = self.selectable.corresponding_column(col, require_embedded=require_embedded)
 
-        if not newcol and col in self.equivalents and col not in _seen:
+        if newcol is None and col in self.equivalents and col not in _seen:
             for equiv in self.equivalents[col]:
                 newcol = self._corresponding_column(equiv, require_embedded=require_embedded, _seen=_seen.union([col]))
-                if newcol:
+                if newcol is not None:
                     return newcol
         return newcol
 
@@ -525,7 +525,7 @@ class ColumnAdapter(ClauseAdapter):
 
     def _locate_col(self, col):
         c = self._corresponding_column(col, False)
-        if not c:
+        if c is None:
             c = self.adapt_clause(col)
             
             # anonymize labels in case they have a hardcoded name
diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py
index 4471d4fb0d..4a54375f8b 100644
--- a/lib/sqlalchemy/sql/visitors.py
+++ b/lib/sqlalchemy/sql/visitors.py
@@ -150,7 +150,7 @@ class ReplacingCloningVisitor(CloningVisitor):
         def replace(elem):
             for v in self._visitor_iterator:
                 e = v.replace(elem)
-                if e:
+                if e is not None:
                     return e
         return replacement_traverse(obj, self.__traverse_options__, replace)
 
@@ -236,7 +236,7 @@ def replacement_traverse(obj, opts, replace):
 
     def clone(element):
         newelem = replace(element)
-        if newelem:
+        if newelem is not None:
             stop_on.add(newelem)
             return newelem
 
diff --git a/lib/sqlalchemy/test/testing.py b/lib/sqlalchemy/test/testing.py
index 374217f9c6..317e3946be 100644
--- a/lib/sqlalchemy/test/testing.py
+++ b/lib/sqlalchemy/test/testing.py
@@ -649,7 +649,7 @@ class ComparesTables(object):
 
         assert len(table.primary_key) == len(reflected_table.primary_key)
         for c in table.primary_key:
-            assert reflected_table.primary_key.columns[c.name]
+            assert reflected_table.primary_key.columns[c.name] is not None
     
     def assert_types_base(self, c1, c2):
         base_mro = sqltypes.TypeEngine.__mro__
diff --git a/test/aaa_profiling/test_zoomark.py b/test/aaa_profiling/test_zoomark.py
index 8a567773f4..282e38ab0e 100644
--- a/test/aaa_profiling/test_zoomark.py
+++ b/test/aaa_profiling/test_zoomark.py
@@ -202,8 +202,8 @@ class ZooMarkTest(TestBase):
                                      ))) == ITERATIONS + 7
 
             # Test now(), today(), year(), month(), day()
-            assert len(fulltable(Zoo.select(Zoo.c.Founded != None
-                                  and Zoo.c.Founded < func.current_timestamp(_type=Date)))) == 3
+            assert len(fulltable(Zoo.select(and_(Zoo.c.Founded != None,
+                                  Zoo.c.Founded < func.current_timestamp(_type=Date))))) == 3
             assert len(fulltable(Animal.select(Animal.c.LastEscape == func.current_timestamp(_type=Date)))) == 0
             assert len(fulltable(Animal.select(func.date_part('year', Animal.c.LastEscape) == 2004))) == 1
             assert len(fulltable(Animal.select(func.date_part('month', Animal.c.LastEscape) == 12))) == 1
diff --git a/test/dialect/test_sqlite.py b/test/dialect/test_sqlite.py
index 448ee947c0..95d14e9a05 100644
--- a/test/dialect/test_sqlite.py
+++ b/test/dialect/test_sqlite.py
@@ -223,7 +223,7 @@ class DialectTest(TestBase, AssertsExecutionResults):
             table1 = Table("django_admin_log", meta, autoload=True)
             table2 = Table("django_content_type", meta, autoload=True)
             j = table1.join(table2)
-            assert j.onclause == table1.c.content_type_id==table2.c.id
+            assert j.onclause.compare(table1.c.content_type_id==table2.c.id)
         finally:
             testing.db.execute("drop table django_admin_log")
             testing.db.execute("drop table django_content_type")
diff --git a/test/engine/test_reflection.py b/test/engine/test_reflection.py
index dff9fa1bb6..48562f6fc7 100644
--- a/test/engine/test_reflection.py
+++ b/test/engine/test_reflection.py
@@ -238,7 +238,7 @@ class ReflectionTest(TestBase, ComparesTables):
 
             assert list(a2.primary_key) == [a2.c.id]
             assert list(u2.primary_key) == [u2.c.id]
-            assert u2.join(a2).onclause == u2.c.id==a2.c.id
+            assert u2.join(a2).onclause.compare(u2.c.id==a2.c.id)
 
             meta3 = MetaData(testing.db)
             u3 = Table('users', meta3, autoload=True)
@@ -249,7 +249,7 @@ class ReflectionTest(TestBase, ComparesTables):
 
             assert list(a3.primary_key) == [a3.c.id]
             assert list(u3.primary_key) == [u3.c.id]
-            assert u3.join(a3).onclause == u3.c.id==a3.c.id
+            assert u3.join(a3).onclause.compare(u3.c.id==a3.c.id)
 
         finally:
             meta.drop_all()
@@ -280,7 +280,7 @@ class ReflectionTest(TestBase, ComparesTables):
             assert [c.parent for c in a2.foreign_keys] == [a2.c.user_id]
             assert [c.parent for c in a2.c.user_id.foreign_keys] == [a2.c.user_id]
             assert list(a2.c.user_id.foreign_keys)[0].parent is a2.c.user_id
-            assert u2.join(a2).onclause == u2.c.id==a2.c.user_id
+            assert u2.join(a2).onclause.compare(u2.c.id==a2.c.user_id)
 
             meta3 = MetaData(testing.db)
             u3 = Table('users', meta3, autoload=True)
@@ -288,7 +288,7 @@ class ReflectionTest(TestBase, ComparesTables):
                 Column('user_id', sa.Integer, sa.ForeignKey('users.id')),
                 autoload=True)
 
-            assert u3.join(a3).onclause == u3.c.id==a3.c.user_id
+            assert u3.join(a3).onclause.compare(u3.c.id==a3.c.user_id)
 
             meta4 = MetaData(testing.db)
             u4 = Table('users', meta4,
@@ -388,14 +388,14 @@ class ReflectionTest(TestBase, ComparesTables):
             u2 = Table('users', meta2, autoload=True)
 
             s = sa.select([a2])
-            assert s.c.user_id
+            assert s.c.user_id is not None
             assert len(a2.foreign_keys) == 1
             assert len(a2.c.user_id.foreign_keys) == 1
             assert len(a2.constraints) == 2
             assert [c.parent for c in a2.foreign_keys] == [a2.c.user_id]
             assert [c.parent for c in a2.c.user_id.foreign_keys] == [a2.c.user_id]
             assert list(a2.c.user_id.foreign_keys)[0].parent is a2.c.user_id
-            assert u2.join(a2).onclause == u2.c.id==a2.c.user_id
+            assert u2.join(a2).onclause.compare(u2.c.id==a2.c.user_id)
 
             meta2 = MetaData(testing.db)
             u2 = Table('users', meta2,
@@ -407,14 +407,14 @@ class ReflectionTest(TestBase, ComparesTables):
                 autoload=True)
 
             s = sa.select([a2])
-            assert s.c.user_id
+            assert s.c.user_id is not None
             assert len(a2.foreign_keys) == 1
             assert len(a2.c.user_id.foreign_keys) == 1
             assert len(a2.constraints) == 2
             assert [c.parent for c in a2.foreign_keys] == [a2.c.user_id]
             assert [c.parent for c in a2.c.user_id.foreign_keys] == [a2.c.user_id]
             assert list(a2.c.user_id.foreign_keys)[0].parent is a2.c.user_id
-            assert u2.join(a2).onclause == u2.c.id==a2.c.user_id
+            assert u2.join(a2).onclause.compare(u2.c.id==a2.c.user_id)
         finally:
             meta.drop_all()
 
@@ -676,9 +676,9 @@ class ReflectionTest(TestBase, ComparesTables):
             assert r1.unique == True
             assert r2.unique == False
             assert r3.unique == False
-            assert [t2.c.id] == r1.columns
-            assert [t2.c.name, t2.c.id] == r2.columns
-            assert [t2.c.name] == r3.columns
+            assert set([t2.c.id]) == set(r1.columns)
+            assert set([t2.c.name, t2.c.id]) == set(r2.columns)
+            assert set([t2.c.name]) == set(r3.columns)
         finally:
             m1.drop_all()
 
diff --git a/test/ext/test_declarative.py b/test/ext/test_declarative.py
index 16a0d697f4..066ce2a9f7 100644
--- a/test/ext/test_declarative.py
+++ b/test/ext/test_declarative.py
@@ -1140,11 +1140,11 @@ class DeclarativeInheritanceTest(DeclarativeTestBase):
         # the exclude_properties collection so that sibling classes
         # don't cross-pollinate.
 
-        assert Person.__table__.c.company_id
-        assert Person.__table__.c.golf_swing
-        assert Person.__table__.c.primary_language
-        assert Engineer.primary_language
-        assert Manager.golf_swing
+        assert Person.__table__.c.company_id is not None
+        assert Person.__table__.c.golf_swing is not None
+        assert Person.__table__.c.primary_language is not None
+        assert Engineer.primary_language is not None
+        assert Manager.golf_swing is not None
         assert not hasattr(Person, 'primary_language')
         assert not hasattr(Person, 'golf_swing')
         assert not hasattr(Engineer, 'golf_swing')
@@ -1204,11 +1204,11 @@ class DeclarativeInheritanceTest(DeclarativeTestBase):
             id = Column(Integer, ForeignKey('people.id'), primary_key=True)
             primary_language = Column(String(50))
 
-        assert Person.__table__.c.golf_swing
+        assert Person.__table__.c.golf_swing is not None
         assert not Person.__table__.c.has_key('primary_language')
-        assert Engineer.__table__.c.primary_language
-        assert Engineer.primary_language
-        assert Manager.golf_swing
+        assert Engineer.__table__.c.primary_language is not None
+        assert Engineer.primary_language is not None
+        assert Manager.golf_swing is not None
         assert not hasattr(Person, 'primary_language')
         assert not hasattr(Person, 'golf_swing')
         assert not hasattr(Engineer, 'golf_swing')
diff --git a/test/orm/inheritance/test_basic.py b/test/orm/inheritance/test_basic.py
index 4f329a91df..a682d38cb1 100644
--- a/test/orm/inheritance/test_basic.py
+++ b/test/orm/inheritance/test_basic.py
@@ -912,8 +912,8 @@ class OverrideColKeyTest(_base.MappedTest):
         # gets joined normally with the extra column.
         
         eq_(
-            class_mapper(Sub).get_property('id').columns,
-            [base.c.base_id, subtable.c.base_id]
+            set(class_mapper(Sub).get_property('id').columns),
+            set([base.c.base_id, subtable.c.base_id])
         )
         
         s1 = Sub()
diff --git a/test/orm/test_manytomany.py b/test/orm/test_manytomany.py
index dcd547f80c..9a51cf3dbd 100644
--- a/test/orm/test_manytomany.py
+++ b/test/orm/test_manytomany.py
@@ -322,7 +322,7 @@ class M2MTest3(_base.MappedTest):
             'a1s': relation(A, secondary=c2a1, lazy=False),
             'a2s': relation(A, secondary=c2a2, lazy=False)})
 
-        assert create_session().query(C).with_labels().statement
+        assert create_session().query(C).with_labels().statement is not None
         
         # TODO: seems like just a test for an ancient exception throw.
         # how about some data/inserts/queries/assertions for this one
diff --git a/test/orm/test_relationships.py b/test/orm/test_relationships.py
index fad25ace56..e8a7f76b12 100644
--- a/test/orm/test_relationships.py
+++ b/test/orm/test_relationships.py
@@ -1293,7 +1293,7 @@ class ViewOnlyLocalRemoteM2M(testing.TestBase):
         compile_mappers()
         assert m.get_property('b_view').local_remote_pairs == \
             m.get_property('b_plain').local_remote_pairs == \
-            [(t1.c.id, t12.c.t1_id), (t12.c.t2_id, t2.c.id)]
+            [(t1.c.id, t12.c.t1_id), (t2.c.id, t12.c.t2_id)]
 
         
     
diff --git a/test/sql/test_defaults.py b/test/sql/test_defaults.py
index 5638dad77f..95e87ecbf8 100644
--- a/test/sql/test_defaults.py
+++ b/test/sql/test_defaults.py
@@ -552,10 +552,11 @@ class SequenceTest(testing.TestBase):
 
         engine = engines.testing_engine(options={'implicit_returning':False})
         result = engine.execute(sometable.insert(), name="somename")
-        assert 'id' in result.postfetch_cols()
+
+        assert set(result.postfetch_cols()) == set([sometable.c.obj_id])
 
         result = engine.execute(sometable.insert(), name="someother")
-        assert 'id' in result.postfetch_cols()
+        assert set(result.postfetch_cols()) == set([sometable.c.obj_id])
 
         sometable.insert().execute(
             {'name':'name3'},
diff --git a/test/sql/test_generative.py b/test/sql/test_generative.py
index 7c094c26b0..0bff777b88 100644
--- a/test/sql/test_generative.py
+++ b/test/sql/test_generative.py
@@ -5,7 +5,7 @@ from sqlalchemy.test import *
 from sqlalchemy.sql.visitors import *
 from sqlalchemy import util
 from sqlalchemy.sql import util as sql_util
-
+from sqlalchemy.test.testing import eq_
 
 class TraversalTest(TestBase, AssertsExecutionResults):
     """test ClauseVisitor's traversal, particularly its ability to copy and modify
@@ -178,7 +178,7 @@ class ClauseTest(TestBase, AssertsCompiledSQL):
 
     def test_binary(self):
         clause = t1.c.col2 == t2.c.col2
-        assert str(clause) == CloningVisitor().traverse(clause)
+        eq_(str(clause), str(CloningVisitor().traverse(clause)))
 
     def test_binary_anon_label_quirk(self):
         t = table('t1', column('col1'))
diff --git a/test/sql/test_select.py b/test/sql/test_select.py
index 9acc94eb28..8e30acf41a 100644
--- a/test/sql/test_select.py
+++ b/test/sql/test_select.py
@@ -1374,7 +1374,12 @@ UNION SELECT mytable.myid FROM mytable WHERE mytable.myid = :myid_2)")
             (t1.c.col1, 'col1', 'mytable.col1', None),
             (column('some wacky thing'), 'some wacky thing', '"some wacky thing"', '')
         ):
-            s1 = select([col], from_obj=getattr(col, 'table', None) or table1)
+            if getattr(col, 'table', None) is not None:
+                t = col.table
+            else:
+                t = table1
+                
+            s1 = select([col], from_obj=t)
             assert s1.c.keys() == [key], s1.c.keys()
         
             if label:
diff --git a/test/sql/test_selectable.py b/test/sql/test_selectable.py
index 95ca0d17bf..147e47cd96 100644
--- a/test/sql/test_selectable.py
+++ b/test/sql/test_selectable.py
@@ -119,9 +119,9 @@ class SelectableTest(TestBase, AssertsExecutionResults):
         u = union(select([table1.c.col1, table1.c.col2, table1.c.col3]), select([table1.c.col1, table1.c.col2, table1.c.col3]))
 
         u = union(select([table1.c.col1, table1.c.col2, table1.c.col3]))
-        assert u.c.col1
-        assert u.c.col2
-        assert u.c.col3
+        assert u.c.col1 is not None
+        assert u.c.col2 is not None
+        assert u.c.col3 is not None
         
     def test_alias_union(self):
         # same as testunion, except its an alias of the union
@@ -188,10 +188,10 @@ class SelectableTest(TestBase, AssertsExecutionResults):
         l1 = select([func.max(table1.c.col1)]).label('foo')
 
         s = select([l1])
-        assert s.corresponding_column(l1).name == s.c.foo
+        eq_(s.corresponding_column(l1), s.c.foo)
         
         s = select([table1.c.col1, l1])
-        assert s.corresponding_column(l1).name == s.c.foo
+        eq_(s.corresponding_column(l1), s.c.foo)
 
     def test_select_alias_labels(self):
         a = table2.select(use_labels=True).alias('a')
@@ -262,12 +262,12 @@ class PrimaryKeyTest(TestBase, AssertsExecutionResults):
         d = Table('d', meta, Column('id', Integer, ForeignKey('c.id'), primary_key=True), Column('x', Integer))
 
         print list(a.join(b, a.c.x==b.c.id).primary_key)
-        assert list(a.join(b, a.c.x==b.c.id).primary_key) == [b.c.id]
+        assert list(a.join(b, a.c.x==b.c.id).primary_key) == [a.c.id]
         assert list(b.join(c, b.c.x==c.c.id).primary_key) == [b.c.id]
         assert list(a.join(b).join(c, c.c.id==b.c.x).primary_key) == [a.c.id]
-        assert list(b.join(c, c.c.x==b.c.id).join(d).primary_key) == [c.c.id]
+        assert list(b.join(c, c.c.x==b.c.id).join(d).primary_key) == [b.c.id]
         assert list(b.join(c, c.c.id==b.c.x).join(d).primary_key) == [b.c.id]
-        assert list(d.join(b, d.c.id==b.c.id).join(c, b.c.id==c.c.x).primary_key) == [c.c.id]
+        assert list(d.join(b, d.c.id==b.c.id).join(c, b.c.id==c.c.x).primary_key) == [b.c.id]
         assert list(a.join(b).join(c, c.c.id==b.c.x).join(d).primary_key) == [a.c.id]
 
         assert list(a.join(b, and_(a.c.id==b.c.id, a.c.x==b.c.id)).primary_key) == [a.c.id]