from django.db import models

class QueryManager(models.Manager):
    def __init__(self, *args, **kwargs):
        if args:
            self._q = args[0]
        else:
            self._q = models.Q(**kwargs)
        super(QueryManager, self).__init__()

    def order_by(self, *args):
        self._order_by = args
        return self

    def get_query_set(self):
        qs = super(QueryManager, self).get_query_set().filter(self._q)
        if hasattr(self, '_order_by'):
            return qs.order_by(*self._order_by)
        return qs