- Fixed SQL compiler's awareness of top-level column labels as used

  in result-set processing; nested selects which contain the same column
  names don't affect the result or conflict with result-column metadata.

- query.get() and related functions (like many-to-one lazyloading)
  use compile-time-aliased bind parameter names, to prevent
  name conflicts with bind parameters that already exist in the
  mapped selectable.

4 files changed, 13 insertions, 9 deletions

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 5e20cf6b6..b68b4c8fe 100644
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -464,9 +464,12 @@ class Mapper(object):
             self.__log("Identified primary key columns: " + str(primary_key))
         
             _get_clause = sql.and_()
+            _get_params = {}
             for primary_key in self.primary_key:
-                _get_clause.clauses.append(primary_key == sql.bindparam(primary_key._label, type_=primary_key.type, unique=True))
-            self._get_clause = _get_clause
+                bind = sql.bindparam(None, type_=primary_key.type)
+                _get_params[primary_key] = bind
+                _get_clause.clauses.append(primary_key == bind)
+            self._get_clause = (_get_clause, _get_params)
 
     def _get_equivalent_columns(self):
         """Create a map of all *equivalent* columns, based on
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index 0d04b768c..f6268579f 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -708,16 +708,17 @@ class Query(object):
             ident = util.to_list(ident)
         params = {}
         
+        (_get_clause, _get_params) = self.select_mapper._get_clause
         for i, primary_key in enumerate(self.primary_key_columns):
             try:
-                params[primary_key._label] = ident[i]
+                params[_get_params[primary_key].key] = ident[i]
             except IndexError:
                 raise exceptions.InvalidRequestError("Could not find enough values to formulate primary key for query.get(); primary key columns are %s" % ', '.join(["'%s'" % str(c) for c in self.primary_key_columns]))
         try:
             q = self
             if lockmode is not None:
                 q = q.with_lockmode(lockmode)
-            q = q.filter(self.select_mapper._get_clause)
+            q = q.filter(_get_clause)
             q = q.params(params)._select_context_options(populate_existing=reload, version_check=(lockmode is not None))
             # call using all() to avoid LIMIT compilation complexity
             return q.all()[0]
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index 5725b5f8e..716a6dbba 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -200,11 +200,11 @@ class DeferredColumnLoader(LoaderStrategy):
                 raise exceptions.InvalidRequestError("Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed" % (instance.__class__, self.key))
 
             if create_statement is None:
-                clause = localparent._get_clause
+                (clause, param_map) = localparent._get_clause
                 ident = instance._instance_key[1]
                 params = {}
                 for i, primary_key in enumerate(localparent.primary_key):
-                    params[primary_key._label] = ident[i]
+                    params[param_map[primary_key].key] = ident[i]
                 statement = sql.select([p.columns[0] for p in group], clause, from_obj=[localparent.mapped_table], use_labels=True)
             else:
                 statement, params = create_statement()
@@ -294,7 +294,7 @@ class LazyLoader(AbstractRelationLoader):
         # determine if our "lazywhere" clause is the same as the mapper's
         # get() clause.  then we can just use mapper.get()
         #from sqlalchemy.orm import query
-        self.use_get = not self.uselist and self.mapper._get_clause.compare(self.lazywhere)
+        self.use_get = not self.uselist and self.mapper._get_clause[0].compare(self.lazywhere)
         if self.use_get:
             self.logger.info(str(self.parent_property) + " will use query.get() to optimize instance loads")
 
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 05c7a5cf4..5572c2ed4 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -240,7 +240,7 @@ class DefaultCompiler(engine.Compiled, visitors.ClauseVisitor):
     def visit_label(self, label):
         labelname = self._truncated_identifier("colident", label.name)
         
-        if self.stack and self.stack[-1].get('select'):
+        if len(self.stack) == 1 and self.stack[-1].get('select'):
             self.typemap.setdefault(labelname.lower(), label.obj.type)
             if isinstance(label.obj, sql._ColumnClause):
                 self.column_labels[label.obj._label] = labelname
@@ -258,7 +258,7 @@ class DefaultCompiler(engine.Compiled, visitors.ClauseVisitor):
         else:
             name = column.name
 
-        if self.stack and self.stack[-1].get('select'):
+        if len(self.stack) == 1 and self.stack[-1].get('select'):
             # if we are within a visit to a Select, set up the "typemap"
             # for this column which is used to translate result set values
             self.typemap.setdefault(name.lower(), column.type)