在查询集上寻找 Django any() 和 all()

Question

我有一个包含 13 个复选框的表单，它们共同构成了我的搜索条件...除了我还添加了一对 ALL 或 ANY 的单选按钮。

我希望能摆脱一些优雅的事情，例如：

priority_ids = request.GET.getlist("priority")  # checkboxes
collection   = request.GET.get("collection")    # radio buttons
priorities = []
for priority_id in priority_ids:
    priorities.append(Q(focus__priority=priority_id))
if   (collection == "any"): qset = any(priorities)
elif (collection == "all"): qset = all(priorities)

但是，any() 和 all() 返回一个布尔值，而不是我可以在过滤器中使用的查询集。我想要一个与“Q(...) | Q(...) | Q(...)”或“Q(...) & Q(.. .) & Q(...)" 适用于 1 到 13 个标准。

Answer 1

Django 无需为此做任何事情。您只需将Q-s 与& 和| 组合起来，以简单的循环或更紧凑的方式与reduce 组合。

关于术语，在我看来，您将Q 称为查询集，但事实并非如此。它是查询集上的过滤器。 像下面这样的东西应该可以工作：

priority_ids = request.GET.getlist("priority")
collection   = request.GET.get("collection")
priority_filters = []
for priority_id in priority_ids:
    priority_filters.append(Q(focus__priority=priority_id))

base_qs = SomeModel.objects.all()

if collection == "any":
   filtered_qset = base_qs.filter(reduce(operator.or_, priority_filters))
elif collection == "all":
   filtered_qset = base_qs.filter(reduce(operator.and_, priority_filters))

Answer 2

您可以使用 Q() 进行动态查询，如下所示...

from django.db.models import Q 
from priority_app.models import Priority  # get your model identified


#(whatever API place you had this):

    priority_id = request.GET.get("priority")   #getlist is isn't a proper list
    field_id = request.query_params.get('collection')
    if priority_id:
        priority_id_list = list(map(str.strip, priority_id.split(",")))


        dynamic_query_filters = Priority.objects.none()
        for a_item in priority_id_list:
            if collection == "any":
                dynamic_query_filters |= (Q(id=a_item))    # OR query
            else:
                dynamic_query_filters &= (Q(id=a_item))   # AND query
    
        queryset = Priority.objects.filter(dynamic_query_filters)   
        # you will notice, it executes in order of "query", maybe take them in different variables and chain them accordingly.