From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 19 Jun 2006 20:41:42 +0000 (+0000)
Subject: when Query does the "nested select" thing, it copies the ORDER BY to be placed on... 
X-Git-Tag: rel_0_2_4~28
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=40e9887b6dd0c1c583831882555340d00473d6b0;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

when Query does the "nested select" thing, it copies the ORDER BY to be placed on the "outer" select, so that eager loaders modify only the outer one and not the inner one
---

diff --git a/CHANGES b/CHANGES
index f08ae12c8f..d5bdb82b30 100644
--- a/CHANGES
+++ b/CHANGES
@@ -9,6 +9,7 @@ the given object was formerly attached to was garbage collected;
 otherwise still requires you explicitly remove the instance from 
 the previous Session.
 - fixes to mapper compilation, checking for more error conditions
+- small fix to eager loading combined with ordering/limit/offset
 
 0.2.3
 - overhaul to mapper compilation to be deferred.  this allows mappers
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index f7d5549008..9111b78ecd 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -324,6 +324,10 @@ class Query(object):
             statement = sql.select([], sql.and_(*crit), from_obj=[self.table], use_labels=True)
  #           raise "OK statement", str(statement)
             if order_by:
+                # copy the order_by, since eager loaders will modify it, and we want the
+                # "inner" order_by to remain untouched
+                # see test/orm/mapper.py EagerTest.testmorelimit
+                order_by = [o.copy_container() for o in util.to_list(order_by)]
                 statement.order_by(*util.to_list(order_by))
         else:
             from_obj.append(self.table)
diff --git a/test/orm/mapper.py b/test/orm/mapper.py
index b73f20b150..13e79bc720 100644
--- a/test/orm/mapper.py
+++ b/test/orm/mapper.py
@@ -795,7 +795,22 @@ class EagerTest(MapperSuperTest):
         l = q.select((Item.c.item_name=='item 2') | (Item.c.item_name=='item 5') | (Item.c.item_name=='item 3'), order_by=[Item.c.item_id], limit=2)        
         self.assert_result(l, Item, *[item_keyword_result[1], item_keyword_result[2]])
         
+    def testmorelimit(self):
+        """tests that the ORDER BY doesnt get clobbered with a nested eager load, when the ORDER BY
+        is an expression.  requires the copying of the order by clause in query.compile()"""
+        ordermapper = mapper(Order, orders, properties = dict(
+                items = relation(mapper(Item, orderitems), lazy = False)
+            ))
+
+        m = mapper(User, users, properties = dict(
+            addresses = relation(mapper(Address, addresses), lazy = False),
+            orders = relation(ordermapper, primaryjoin = users.c.user_id==orders.c.user_id, lazy = False),
+        ))
+        sess = create_session()
+        q = sess.query(m)
         
+        l = q.select(q.join_to('orders'), order_by=desc(orders.c.user_id), limit=2, offset=1)
+        self.assert_result(l, User, *(user_all_result[2], user_all_result[0]))
         
     def testonetoone(self):
         m = mapper(User, users, properties = dict(