From a4ba9b5414ee3d18667b67d57a361845a8354d3c Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 28 Feb 2006 23:18:43 +0000
Subject: [PATCH] oid inits at compilation time/when needed again, added a unit
 test

---
 lib/sqlalchemy/ext/proxy.py |  6 ++----
 lib/sqlalchemy/sql.py       |  8 ++++----
 test/proxy_engine.py        | 11 +++++++++++
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/lib/sqlalchemy/ext/proxy.py b/lib/sqlalchemy/ext/proxy.py
index d9a830c66e..783ea969e8 100644
--- a/lib/sqlalchemy/ext/proxy.py
+++ b/lib/sqlalchemy/ext/proxy.py
@@ -28,10 +28,8 @@ class BaseProxyEngine(object):
         return "%s(%s)" % (self.__class__.__name__, id(self))
 
     def oid_column_name(self):
-        # NOTE: setting up mappers fails unless the proxy engine returns
-        # something for oid column name, and the call happens too early
-        # to proxy, so effecticely no oids are allowed when using
-        # proxy engine
+        # oid_column should not be requested before the engine is connected.
+        # it should ideally only be called at query compilation time.
         e= self.get_engine()
         if e is None:
             return None
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index f905da5834..6b574861be 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -827,7 +827,9 @@ class Join(FromClause):
         else:
             self.onclause = onclause
         self.isouter = isouter
-        self.oid_column = self.left.oid_column
+
+    oid_column = property(lambda s:s.left.oid_column)
+    
     def _exportable_columns(self):
         return [c for c in self.left.columns] + [c for c in self.right.columns]
     def _proxy_column(self, column):
@@ -1001,6 +1003,7 @@ class TableClause(FromClause):
             if self.engine.oid_column_name() is not None:
                 self._oid_column = schema.Column(self.engine.oid_column_name(), sqltypes.Integer, hidden=True)
                 self._oid_column._set_parent(self)
+                self._orig_columns()[self._oid_column.original] = self._oid_column
             else:
                 self._oid_column = None
         return self._oid_column
@@ -1011,9 +1014,6 @@ class TableClause(FromClause):
             self._orig_cols= {}
             for c in self.columns:
                 self._orig_cols[c.original] = c
-            oid = self.oid_column
-            if oid is not None:
-                self._orig_cols[oid.original] = oid
             return self._orig_cols
     columns = property(lambda s:s._columns)
     c = property(lambda s:s._columns)
diff --git a/test/proxy_engine.py b/test/proxy_engine.py
index 2ef19fc075..14cd1902bc 100644
--- a/test/proxy_engine.py
+++ b/test/proxy_engine.py
@@ -22,6 +22,17 @@ class User(object):
     pass
 
 
+class ConstructTest(PersistTest):
+    """tests that we can build SQL constructs without engine-specific parameters, particulary
+    oid_column, being needed, as the proxy engine is usually not connected yet."""
+    def test_join(self):
+        engine = ProxyEngine()
+        t = Table('table1', engine, 
+            Column('col1', Integer, primary_key=True))
+        t2 = Table('table2', engine, 
+            Column('col2', Integer, ForeignKey('table1.col1')))
+        j = join(t, t2)
+        
 class ProxyEngineTest1(PersistTest):
 
     def setUp(self):
-- 
2.47.2