Exception handling for database queries

ref-test/app/tools/test.py

@@ -1,8 +1,10 @@
 from .data import randomise_list
 from ..models import Entry
+from ..tools.logs import write
 
-from flask import redirect, request, session
-from flask.helpers import url_for
+from flask import request, session
+from flask.helpers import abort, redirect, url_for
+from sqlalchemy.exc import SQLAlchemyError
 
 from functools import wraps
 
@@ -129,8 +131,11 @@ def redirect_if_started(function):
     @wraps(function)
     def wrapper(*args, **kwargs):
         id = session.get('id')
-        if request.method == 'GET' and id and Entry.query.filter_by(id=id).first():
-            return redirect(url_for('quiz._quiz'))
+        try:
+            if request.method == 'GET' and id and Entry.query.filter_by(id=id).first(): return redirect(url_for('quiz._quiz'))
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when checking if test has been started: {exception}')
+            return abort(500)
         return function(*args, **kwargs)
     return wrapper