python - Django Q, icontains not working -

i've following simple code searching blog:

def searchview(request):     template_name = 'search_results.html'      q = request.get.get('q', none)     if q none or q == '':         return redirect('/')      object_list = []      query = (q(title__istartswith=q) | q(title__icontains=q) |              q(content__istartswith=q) | q(content__icontains=q))      models = contenttype.objects.filter(         model__in=settings.searchable_objects).all()     model in models:         obj = model.get_all_objects_for_this_type().filter(query).all()         object_list = chain(object_list, obj)      objects = list(object_list)      context = {'posts': objects, 'q': q}     template = template_name     return render(request, template, context) 

and when query bangkok, posts containing bangkok. if query bangkok, nothing returned. in django documentation, says icontains should ignore case, doesn't work me.

i use sqlite, , need db engine.

any ideas? grateful!