如何创建一个基于Django中的单个条件过滤多个字段的查询集？

Question

我的模特是

class TestModel(models.Model) 
    field1 = models.IntegerField()
    field2 = models.IntegerField()
    field3 = models.IntegerField()
    field4 = models.IntegerField()
    field5 = models.IntegerField()

我需要一个简单的查询集,它在模型的所有五个字段上应用单个条件,而无需编写每个字段组合并过滤它们.

例如,我想将检查None的条件应用于两个或更多字段

TestModel.objects.filter(two_or_more_fields=None)

我不想编写5个字段的每个可能组合来查找任何两个或多个字段为None的查询集.换句话说,有没有比这更好的方法:

from django.db.models import Q
TestModel.objects.filter(
    #condition for exactly 2 None
    Q(field1=None & field2=None) |
    Q(field2=None & field3=None) |
    Q(field3=None & field4=None) |
    Q(field4=None & field5=None) |
    Q(field5=None & field1=None) |
    #condition for more than 2 None
    Q(field1=None & field2=None & field3 = None) |
    '''''
    .
    .
    #so on to cover all possible cases of any two or more fields as None
     )

我认为应该有一种更好,更简单的方法来实现这一目标.

Answer 1

花了几个小时后，我找不到使用内置 Django 过滤器构造来完成此操作的简单方法。但是我发现这个解决方案更接近我正在寻找的解决方案：

field_list = ['field1', 'field2', 'field3', 'field4', 'field5']

def get_all_possible_filter_dict_list_for_a_condition(field_list):

    all_possible_filter_dict_for_a_condition = []
    for field_1, field_2 in combinations(field_list, 2):
        all_possible_filter_dict_for_a_condition.append(
        {
         field_1:None,
         field_2:None 
         }
        )
    return all_possible_filter_dict_for_a_condition


def get_qs_list_to_perform_or_operation(all_possible_filter_dict_list_for_a_condition):

    qs_list_to_perform_or_operation = []
    for i, filter_dict in enumerate(all_possible_filter_dict_list_for_a_condition):
       qs_to_append = qs.filter(**filter_dict)
       qs_list_to_perform_or_operation.append(qs_to_append)
    return qs_list_to_perform_or_operation


def get_qs_to_filter_fields_with_more_than_1_none(qs_list_to_perform_or_operation ):

    final_qs = qs_list_to_perform_or_operation [0]
    for i in range(len(qs_list_to_perform_or_operation ) - 1):
        final_qs = final_qs | qs_list[i + 1]
    return final_qs

all_possible_filter_dict_list_for_a_condition 
   = get_all_possible_filter_dict_list_for_a_condition(field_list)
qs_list_to_perform_or_operation = get_qs_list_to_perform_or_operation(all_possible_filter_dict_list_for_a_condition)
final_qs_to_filter_multiple_fields_with_same_condtion = get_qs_to_filter_fields_with_more_than_1_none(qs_list_to_perform_or_operation)