- add further coverage for join_condition to make sure we get this case where

there are multiple, equivalent foreign keys

2 files changed, 11 insertions, 1 deletions

diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index ce48d4c4b..f64a70ec8 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -740,7 +740,7 @@ class Join(FromClause):
             if len(constraints) > 1:
                 dedupe = set(tuple(crit) for crit in constraints.values())
                 if len(dedupe) == 1:
-                    key = constraints.keys()[0]
+                    key = list(constraints)[0]
                     constraints = {key: constraints[key]}
 
             if len(constraints) != 1:
diff --git a/test/sql/test_selectable.py b/test/sql/test_selectable.py
index 5d3d53b88..a5693acd3 100644
--- a/test/sql/test_selectable.py
+++ b/test/sql/test_selectable.py
@@ -1062,6 +1062,16 @@ class JoinConditionTest(fixtures.TestBase, AssertsCompiledSQL):
                 "FROM t2 JOIN t3 ON t2.id = t3.t2id) ON t2.id = t3_t2id")
 
 
+    def test_join_multiple_equiv_fks(self):
+        m = MetaData()
+        t1 = Table('t1', m,
+                Column('id', Integer, primary_key=True)
+            )
+        t2 = Table('t2', m,
+                Column('t1id', Integer, ForeignKey('t1.id'), ForeignKey('t1.id'))
+                )
+
+        assert sql_util.join_condition(t1, t2).compare(t1.c.id == t2.c.t1id)
 
     def test_join_cond_no_such_unrelated_table(self):
         m = MetaData()