From a3a85ed54f0a3b99037b6ed25ac6c3c16d3b221c Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Fri, 2 Apr 2010 12:42:54 -0400
Subject: [PATCH] - Declarative will raise an informative error message if a
 non-mapped class attribute is referenced in the string-based relationship()
 arguments.

---
 CHANGES                           |  4 ++++
 lib/sqlalchemy/ext/declarative.py |  8 ++++++--
 test/ext/test_declarative.py      | 17 +++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index f22905f267..fc217179c6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -49,6 +49,10 @@ CHANGES
      decorators on child classes that aren't broken by a 
      @compiles decorator on the base class.
    
+   - Declarative will raise an informative error message
+     if a non-mapped class attribute is referenced in the
+     string-based relationship() arguments.
+     
 0.6beta3
 ========
 
diff --git a/lib/sqlalchemy/ext/declarative.py b/lib/sqlalchemy/ext/declarative.py
index 1f4658b605..407de10046 100644
--- a/lib/sqlalchemy/ext/declarative.py
+++ b/lib/sqlalchemy/ext/declarative.py
@@ -749,8 +749,12 @@ class _GetColumns(object):
         
         mapper = class_mapper(self.cls, compile=False)
         if mapper:
-            prop = mapper.get_property(key)
-            if not isinstance(prop, ColumnProperty):
+            prop = mapper.get_property(key, raiseerr=False)
+            if prop is None:
+                raise exceptions.InvalidRequestError(
+                                        "Class %r does not have a mapped column named %r"
+                                        % (self.cls, key))
+            elif not isinstance(prop, ColumnProperty):
                 raise exceptions.InvalidRequestError(
                                         "Property %r is not an instance of"
                                         " ColumnProperty (i.e. does not correspond"
diff --git a/test/ext/test_declarative.py b/test/ext/test_declarative.py
index 01ce7a6357..d5d837da7f 100644
--- a/test/ext/test_declarative.py
+++ b/test/ext/test_declarative.py
@@ -187,6 +187,23 @@ class DeclarativeTest(DeclarativeTestBase):
             rel = relationship("User", primaryjoin="User.addresses==Foo.id")
         assert_raises_message(exc.InvalidRequestError, "'addresses' is not an instance of ColumnProperty", compile_mappers)
 
+    def test_string_dependency_resolution_two(self):
+        class User(Base, ComparableEntity):
+            __tablename__ = 'users'
+            id = Column(Integer, primary_key=True, test_needs_autoincrement=True)
+            name = Column(String(50))
+            addresses = relationship("Address", order_by="desc(Address.email)", 
+                primaryjoin="User.id==Address.user_id", foreign_keys="[Address.user_id]",
+                backref=backref('user', primaryjoin="User.id==Address.user_id", foreign_keys="[Address.user_id]")
+                )
+        
+        
+        class Bar(Base, ComparableEntity):
+            __tablename__ = 'bar'
+            id = Column(Integer, primary_key=True)
+            rel = relationship("User", primaryjoin="User.id==Bar.__table__.id")
+        assert_raises_message(exc.InvalidRequestError, "does not have a mapped column named '__table__'", compile_mappers)
+
     def test_string_dependency_resolution_no_magic(self):
         """test that full tinkery expressions work as written"""
         
-- 
2.47.3