diff --git a/neutron_taas/db/taas_db.py b/neutron_taas/db/taas_db.py
index 12fc3b19..f39737ab 100644
--- a/neutron_taas/db/taas_db.py
+++ b/neutron_taas/db/taas_db.py
@@ -161,8 +161,8 @@ class Taas_db_Mixin(taas_extension.TaasPluginBase):
             return
 
         ns_data = {
-            'physical_network': ns['physical_network'],
-            'network_type': ns['network_type']
+            'physical_network': ns[1],
+            'network_type': ns[2]
         }
         return ns_data
 
diff --git a/neutron_taas/tests/unit/db/test_taas_db.py b/neutron_taas/tests/unit/db/test_taas_db.py
index d97d0f9e..a7b658d2 100644
--- a/neutron_taas/tests/unit/db/test_taas_db.py
+++ b/neutron_taas/tests/unit/db/test_taas_db.py
@@ -60,54 +60,54 @@ class TaaSDbTestCase(testlib_api.SqlTestCase):
 
     def _get_tap_service(self, tap_service_id):
         """Helper method to retrieve tap service."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.get_tap_service(self.ctx, tap_service_id)
 
     def _get_tap_services(self):
         """Helper method to retrieve all tap services."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.get_tap_services(self.ctx)
 
     def _create_tap_service(self, tap_service):
         """Helper method to create tap service."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.create_tap_service(self.ctx, tap_service)
 
     def _update_tap_service(self, tap_service_id, tap_service):
         """Helper method to update tap service."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.update_tap_service(self.ctx,
                                                  tap_service_id,
                                                  tap_service)
 
     def _delete_tap_service(self, tap_service_id):
         """Helper method to delete tap service."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.delete_tap_service(self.ctx, tap_service_id)
 
     def _get_tap_flow(self, tap_flow_id):
         """Helper method to retrieve tap flow."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.get_tap_flow(self.ctx, tap_flow_id)
 
     def _get_tap_flows(self):
         """Helper method to retrieve all tap flows."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.get_tap_flows(self.ctx)
 
     def _create_tap_flow(self, tap_flow):
         """Helper method to create tap flow."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.create_tap_flow(self.ctx, tap_flow)
 
     def _update_tap_flow(self, tap_flow_id, tap_flow):
         """Helper method to update tap flow."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.update_tap_flow(self.ctx, tap_flow_id, tap_flow)
 
     def _delete_tap_flow(self, tap_flow_id):
         """Helper method to delete tap flow."""
-        with self.ctx.session.begin(subtransactions=True):
+        with self.ctx.session.begin():
             return self.mixin.delete_tap_flow(self.ctx, tap_flow_id)
 
     def test_tap_service_get(self):