diff --git a/quantum/db/securitygroups_db.py b/quantum/db/securitygroups_db.py
index b8678cfef4..f160522c44 100644
--- a/quantum/db/securitygroups_db.py
+++ b/quantum/db/securitygroups_db.py
@@ -38,7 +38,9 @@ class SecurityGroup(model_base.BASEV2, models_v2.HasId, models_v2.HasTenant):
 
 class SecurityGroupPortBinding(model_base.BASEV2):
     """Represents binding between quantum ports and security profiles"""
-    port_id = sa.Column(sa.String(36), sa.ForeignKey("ports.id"),
+    port_id = sa.Column(sa.String(36),
+                        sa.ForeignKey("ports.id",
+                                      ondelete='CASCADE'),
                         primary_key=True)
     security_group_id = sa.Column(sa.String(36),
                                   sa.ForeignKey("securitygroups.id"),
@@ -287,9 +289,6 @@ class SecurityGroupDbMixin(ext_sg.SecurityGroupPluginBase):
                 rule.get('external_id')):
                 raise ext_sg.SecurityGroupNotProxyMode()
 
-            protocol = rule.get('protocol')
-            ethertype = rule.get('ethertype')
-
             # Check that port_range's are valid
             if (rule['port_range_min'] is None and
                 rule['port_range_max'] is None):
diff --git a/quantum/tests/unit/test_extension_security_group.py b/quantum/tests/unit/test_extension_security_group.py
index baff8188ec..9d3fa756d1 100644
--- a/quantum/tests/unit/test_extension_security_group.py
+++ b/quantum/tests/unit/test_extension_security_group.py
@@ -19,21 +19,13 @@ import os
 import mock
 import webob.exc
 
-from quantum.api.extensions import PluginAwareExtensionManager
-from quantum.api.v2 import attributes
-from quantum.api.v2.router import APIRouter
-from quantum.common import config
 from quantum.common.test_lib import test_config
 from quantum import context
-from quantum.db import api as db
 from quantum.db import db_base_plugin_v2
 from quantum.db import securitygroups_db
 from quantum.extensions import securitygroup as ext_sg
-from quantum.manager import QuantumManager
 from quantum.openstack.common import cfg
 from quantum.tests.unit import test_db_plugin
-from quantum.tests.unit import test_extensions
-from quantum.wsgi import JSONDeserializer
 
 DB_PLUGIN_KLASS = ('quantum.tests.unit.test_extension_security_group.'
                    'SecurityGroupTestPlugin')
@@ -200,12 +192,6 @@ class SecurityGroupTestPlugin(db_base_plugin_v2.QuantumDbPluginV2,
             self._extend_port_dict_security_group(context, port)
         return port
 
-    def delete_port(self, context, id):
-        session = context.session
-        with session.begin(subtransactions=True):
-            self._delete_port_security_group_bindings(context, id)
-            super(SecurityGroupTestPlugin, self).delete_port(context, id)
-
     def create_network(self, context, network):
         tenant_id = self._get_tenant_id_for_create(context, network['network'])
         self._ensure_default_security_group(context, tenant_id)