Include connection errors in exception handling

ref-test/app/quiz/views.py

@@ -40,7 +40,7 @@ def _start():
             entry.set_email(request.form.get('email'))
             code = request.form.get('test_code').replace('—', '').lower()
             try: test = Test.query.filter_by(code=code).first()
-            except SQLAlchemyError as exception:
+            except (SQLAlchemyError, ConnectionError) as exception:
                 write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
                 return abort(500)
             entry.test = test
@@ -69,7 +69,7 @@ def _quiz():
             flash('Your session was not recognised. Please sign in to the quiz again.', 'error')
             session.pop('id', None)
             return redirect(url_for('quiz._start'))
-    except SQLAlchemyError as exception:
+    except (SQLAlchemyError, ConnectionError) as exception:
         write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
         return abort(500)
     return render_template('/quiz/client.html')
@@ -78,7 +78,7 @@ def _quiz():
 def _result():
     id = session.get('id')
     try: entry = Entry.query.filter_by(id=id).first()
-    except SQLAlchemyError as exception:
+    except (SQLAlchemyError, ConnectionError) as exception:
         write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
         return abort(500)
     if not entry: return abort(404)