django - 通过排序获取查询集的当前order_

Question

我想在给定主键的查询集中找到相邻项，如here所问。但是，我希望此方法适用于任何给定的查询集，但我尚未为自己设置顺序。如何找到__gt和__lt过滤的查询集的当前顺序？

例如:

queryset = MyModel.objects.all().order_by('some_field')
next_obj = get_next(queryset, after_pk, 10)
...
def get_next(queryset, pk, n):
    #ordering is unknown here
    obj = queryset.get(pk=pk)
    field = queryset.get_order_by_field_name() #???
    return queryset.filter(**{field+'__gt': getattr(obj, field)})[:n]

该模型可以定义一个默认的 ordering，并且我可以检查queryset是否为 ordered，但是在这种情况下我都不认为这有帮助。

Answer 1

您可以通过访问queryset.query.order_by属性从order_by子句中检索列的列表。

从Django文档中:

The query attribute is an opaque object. It represents the internals of the query construction and is not part of the public API. However, it is safe (and fully supported) to pickle and unpickle the attribute’s contents as described here.