- The Column.references() method now returns True

if it has a foreign key referencing the
given column exactly, not just it's parent
table.  [ticket:2064]

3 files changed, 52 insertions, 1 deletions

diff --git a/CHANGES b/CHANGES
index 718677afc..3d834b330 100644
--- a/CHANGES
+++ b/CHANGES
@@ -29,6 +29,11 @@ CHANGES
     metadata.create_all() and metadata.drop_all(), 
     including "checkfirst" logic.  [ticket:2055]
 
+  - The Column.references() method now returns True
+    if it has a foreign key referencing the
+    given column exactly, not just it's parent
+    table.  [ticket:2064]
+
 - ext
   - Association proxy now has correct behavior for
     any(), has(), and contains() when proxying
diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py
index 40d7de945..e6b970291 100644
--- a/lib/sqlalchemy/schema.py
+++ b/lib/sqlalchemy/schema.py
@@ -766,7 +766,7 @@ class Column(SchemaItem, expression.ColumnClause):
         key."""
 
         for fk in self.foreign_keys:
-            if fk.references(column.table):
+            if fk.column.proxy_set.intersection(column.proxy_set):
                 return True
         else:
             return False
diff --git a/test/sql/test_metadata.py b/test/sql/test_metadata.py
index 38788330a..ace3b69d5 100644
--- a/test/sql/test_metadata.py
+++ b/test/sql/test_metadata.py
@@ -500,6 +500,52 @@ class TableTest(TestBase, AssertsCompiledSQL):
             assign
         )
 
+class ConstraintTest(TestBase):
+    def _single_fixture(self):
+        m = MetaData()
+
+        t1 = Table('t1', m, 
+            Column('a', Integer),
+            Column('b', Integer)
+        )
+
+        t2 = Table('t2', m, 
+            Column('a', Integer, ForeignKey('t1.a'))
+        )
+
+        t3 = Table('t3', m, 
+            Column('a', Integer)
+        )
+        return t1, t2, t3
+
+    def test_table_references(self):
+        t1, t2, t3 = self._single_fixture()
+        assert list(t2.c.a.foreign_keys)[0].references(t1)
+        assert not list(t2.c.a.foreign_keys)[0].references(t3)
+
+    def test_column_references(self):
+        t1, t2, t3 = self._single_fixture()
+        assert t2.c.a.references(t1.c.a)
+        assert not t2.c.a.references(t3.c.a)
+        assert not t2.c.a.references(t1.c.b)
+
+    def test_column_references_derived(self):
+        t1, t2, t3 = self._single_fixture()
+        s1 = tsa.select([tsa.select([t1]).alias()])
+        assert t2.c.a.references(s1.c.a)
+        assert not t2.c.a.references(s1.c.b)
+
+    def test_copy_doesnt_reference(self):
+        t1, t2, t3 = self._single_fixture()
+        a2 = t2.c.a.copy()
+        assert not a2.references(t1.c.a)
+        assert not a2.references(t1.c.b)
+
+    def test_derived_column_references(self):
+        t1, t2, t3 = self._single_fixture()
+        s1 = tsa.select([tsa.select([t2]).alias()])
+        assert s1.c.a.references(t1.c.a)
+        assert not s1.c.a.references(t1.c.b)
 
 class ColumnDefinitionTest(TestBase):
     """Test Column() construction."""