Fix has_index, fixes #148

- Make has_index work with tables without primary keys

CHANGES.rst

@@ -4,6 +4,12 @@ Changelog
 Here you can see the full list of changes between each SQLAlchemy-Utils release.
 
 
+0.30.8 (2015-06-xx)
+^^^^^^^^^^^^^^^^^^^
+
+- Make has_index work with tables without primary keys (#148)
+
+
 0.30.7 (2015-05-28)
 ^^^^^^^^^^^^^^^^^^^
 

sqlalchemy_utils/functions/database.py

@@ -247,8 +247,9 @@ def has_index(column):
             'Only columns belonging to Table objects are supported. Given '
             'column belongs to %r.' % table
         )
+    primary_keys = table.primary_key.columns.values()
     return (
-        column is table.primary_key.columns.values()[0]
+        (primary_keys and column is primary_keys[0])
         or
         any(
             index.columns.values()[0] is column

tests/functions/test_has_index.py

@@ -39,3 +39,14 @@ class TestHasIndex(object):
     def test_compound_column_index(self):
         assert has_index(self.table.c.is_deleted)
         assert not has_index(self.table.c.is_archived)
+
+    def test_table_without_primary_key(self):
+        Base = declarative_base()
+
+        article = sa.Table(
+            'article',
+            sa.MetaData(),
+            sa.Column('name', sa.String)
+        )
+
+        assert not has_index(article.c.name)