Django Rest Framework的批量，部分更新 [英] Bulk, partial updates with Django Rest Framework

问题描述

我想一次部分更新多个项目。我已经添加了一个mixin以允许我批量创建（并且效果很好），但是即使我添加了部分参数，也不允许修补列表。

I want to partially-update multiple items at once. I've already added a mixin for allowing me to bulk-create (and that works well) but even though I've added a partial argument, it doesn't allow for patching a list.

我猜这是一个路由问题。我需要一个新的视图来处理 / 上的PATCH（而不是 / id / ），但我很满意

I'm guessing that this is a routing issue. I need a new view to handle PATCH on / (rather than /id/), but I'm well out of my depth.

现有的答案在3.8版本中无效，或者至少没有对我有效。我需要对以下内容做什么？

Existing answers for this don't work for 3.8, or at least haven't worked for me. What do I need to do to the following?

class ResourceSerializer(serializers.ModelSerializer):
    class Meta:
        model = Resource
        fields = ('id', 'name', ...)
        read_only_fields = ('id',)

 class BulkMixin:
     def get_serializer(self, *args, **kwargs):
        if isinstance(kwargs.get('data', {}), list):
            kwargs['many'] = True
            kwargs['partial'] = True

        return super().get_serializer(*args, **kwargs)

class ResourceViewSet(BulkMixin, viewsets.ModelViewSet):
    serializer_class = ResourceSerializer

推荐答案

〜10之后数小时将我的头撞在墙上，我决定正确的方式可以坐到后面，而我会用可行的破解方式来弥补。我添加了以下内容

After ~10 hours banging my head against this wall, I decided that the right way could take a back seat and I'd make do with the hack way that works. I added the following gnarlfest to my viewset.

from rest_framework.decorators import action

@action(methods=['patch'], detail=False)
def bulk_update(self, request):

    data = {  # we need to separate out the id from the data
        i['id']: {k: v for k, v in i.items() if k != 'id'}
        for i in request.data
    }

    for inst in self.get_queryset().filter(id__in=data.keys()):
        serializer = self.get_serializer(inst, data=data[inst.id], partial=True)
        serializer.is_valid(raise_exception=True)
        serializer.save()

    return Response({})

如果我在 [{id：123，otherfield：" abc"}，...] 现在将进行批量部分更新。我相当确定这是在执行n + 1个查询，并且原始ORM的效率要高得多……但目前，它比n个请求更好。另外，如果该ID不在查询集中，则它将通过而不是出错。

If I patch in a list of [{id: 123, otherfield: "abc"}, ...] this will now bulk-partial update. I'm fairly sure this is doing n+1 queries and that it'd be a lot more efficient in raw ORM... but for now, it's infinitely better than n requests. Also, if the ID isn't in the queryset, it will pass over rather than erroring. That works for me, but may not for others.

我会在48小时内悬赏该问题，以吸引一些好的答案。

I'll stick a bounty on this question in 48h to tempt in some good answers.

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