serious overhaul to get eager loads to work inline with an inheriting mapper, when the inheritance/eager loads share the same table. mapper inheritance will also favor the columns from the child table over those of the parent table when assigning column values to object attributes. "correlated subqueries" require a flag "correlated=True" if they are in the FROM clause of another SELECT statement, and they want to be correlated. this flag is set by default when using an "exists" clause.

1 files changed, 15 insertions, 8 deletions

diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index 73481009d..04949c935 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -129,6 +129,7 @@ def between_(ctest, cleft, cright):
     return BooleanExpression(ctest, and_(cleft, cright), 'BETWEEN')
         
 def exists(*args, **params):
+    params['correlate'] = True
     s = select(*args, **params)
     return BooleanExpression(TextClause("EXISTS"), s, None)
 
@@ -839,7 +840,7 @@ class Join(FromClause):
         self.left = left
         self.right = right
         self.id = self.left.id + "_" + self.right.id
-
+        
         # TODO: if no onclause, do NATURAL JOIN
         if onclause is None:
             self.onclause = self._match_primaries(left, right)
@@ -852,7 +853,7 @@ class Join(FromClause):
     def _exportable_columns(self):
         return [c for c in self.left.columns] + [c for c in self.right.columns]
     def _proxy_column(self, column):
-        self._columns[column.table.name + "_" + column.key] = column
+        self._columns[column._label] = column
         if column.primary_key:
             self._primary_key.append(column)
         if column.foreign_key:
@@ -894,7 +895,9 @@ class Join(FromClause):
             self.join = join
         def _exportable_columns(self):
             return []
-                
+    
+    def alias(self, name=None):
+        return self.select(use_labels=True).alias(name)            
     def _process_from_dict(self, data, asfrom):
         for f in self.onclause._get_from_objects():
             data[f.id] = f
@@ -915,7 +918,7 @@ class Alias(FromClause):
         self.original = baseselectable
         self.selectable = selectable
         if alias is None:
-            n = getattr(self.original, 'name')
+            n = getattr(self.original, 'name', None)
             if n is None:
                 n = 'anon'
             elif len(n) > 15:
@@ -974,7 +977,7 @@ class ColumnClause(ColumnElement):
         self.__label = None
     def _get_label(self):
         if self.__label is None:
-            if self.table is not None:
+            if self.table is not None and self.table.name is not None:
                 self.__label =  self.table.name + "_" + self.text
             else:
                 self.__label = self.text
@@ -1164,7 +1167,7 @@ class CompoundSelect(SelectBaseMixin, FromClause):
 class Select(SelectBaseMixin, FromClause):
     """represents a SELECT statement, with appendable clauses, as well as 
     the ability to execute itself and return a result set."""
-    def __init__(self, columns=None, whereclause = None, from_obj = [], order_by = None, group_by=None, having=None, use_labels = False, distinct=False, engine = None, limit=None, offset=None):
+    def __init__(self, columns=None, whereclause = None, from_obj = [], order_by = None, group_by=None, having=None, use_labels = False, distinct=False, engine = None, limit=None, offset=None, correlate=False):
         self._froms = util.OrderedDict()
         self.use_labels = use_labels
         self.id = "Select(%d)" % id(self)
@@ -1175,6 +1178,7 @@ class Select(SelectBaseMixin, FromClause):
         self.oid_column = None
         self.limit = limit
         self.offset = offset
+        self.correlate = correlate
         
         # indicates if this select statement is a subquery inside another query
         self.issubquery = False
@@ -1224,9 +1228,11 @@ class Select(SelectBaseMixin, FromClause):
             select.is_where = self.is_where
             select.issubquery = True
             select.parens = True
+            if not self.is_where and not select.correlate:
+                return
             if getattr(select, '_correlated', None) is None:
                 select._correlated = self.select._froms
-
+                
     def append_column(self, column):
         if _is_literal(column):
             column = ColumnClause(str(column), self)
@@ -1266,7 +1272,8 @@ class Select(SelectBaseMixin, FromClause):
     def append_from(self, fromclause):
         if type(fromclause) == str:
             fromclause = FromClause(from_name = fromclause)
-
+        if self.oid_column is None and hasattr(fromclause, 'oid_column'):
+            self.oid_column = fromclause.oid_column
         fromclause.accept_visitor(self._correlator)
         fromclause._process_from_dict(self._froms, True)