更新 Django REST 框架中 ManyToMany 字段的数组

Question

我有一个模型 Plot，它看起来像这样：

from django.db import models


class Plot(models.Model):
    class SUNSHINE(models.TextChoices):
        NONE = None
        FULL_SUN = 'Plein soleil',
        SHADOW = "Dans l'ombre",
        SUNNY = 'Ensoleillée',
        MODERATE = 'Modérée'

    name = models.CharField(max_length=50)
    garden = models.ForeignKey('perma_gardens.Garden', on_delete=models.CASCADE)
    width = models.CharField(max_length=50, blank=True, null=True)
    height = models.CharField(max_length=50, blank=True, null=True)

    exposition = models.CharField(max_length=50, choices=SUNSHINE.choices, default=SUNSHINE.NONE, blank=True,
                                  null=True)

    qr_code = models.CharField(max_length=50, blank=True, null=True)

    plant = models.ManyToManyField('perma_plants.Plant', related_name='%(class)s_plant', blank=True)

    def __str__(self):
        return self.name

带有一个 plant 对象，它是同名模型的外键。在我看来，我有这个 partial_update 函数：

class PlotViewSet(viewsets.ModelViewSet):
    permission_classes = (IsAuthenticated,)
    queryset = Plot.objects.all()

    def partial_update(self, request, *args, **kwargs):
        instance = self.queryset.get(pk=kwargs.get('pk'))
        serializer = WritePlotSerializer(instance, data=request.data, partial=True)
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(serializer.data)

但是，当我在我面前想要更新我的地块中的植物时，我可以 select 几个，当我点击添加时它会更新，但它删除了现有的旧植物或者我希望当我更新时，它保留数组中已经存在的植物，然后添加我们刚刚添加的植物。我怎样才能得到这个结果？

这是我的 Plot 模型的序列化程序：

from rest_framework import serializers
from .models import Plot
from apps.perma_plants.models import Plant
from apps.perma_gardens.models import Garden
from apps.perma_plant_categories.models import PlantCategory


class GardenSerializer(serializers.ModelSerializer):

    class Meta:
        model = Garden
        fields = ('id', 'name',)

class PlantSerializer(serializers.ModelSerializer):
    class Meta:
        model = Plant
        fields = ('id', 'name', "category", 'image', 'facility_rate', 'sunshine_index', 'irrigation_index')

class ReadPlotSerializer(serializers.ModelSerializer):
    garden = GardenSerializer(required=True)
    plant = PlantSerializer(many=True)
    id = serializers.IntegerField(read_only=True)

    class Meta:
        model = Plot
        fields = '__all__'
        read_only_fields = [fields]

class WritePlotSerializer(serializers.ModelSerializer):

    class Meta:
        model = Plot
        fields = '__all__'

感谢您的反馈！

Answer 1

有几种方法可以解决这个问题：

1- 在请求中发送整个数组

2- 使用一些验证器向序列化程序添加逻辑。参考

更新：我删除了#3，因为我忘记了 SerializerMethodField 是 read-only。对不起。

文档：https://www.django-rest-framework.org/api-guide/serializers/#validation

更新 Django REST 框架中 ManyToMany 字段的数组

Update array of ManyToMany field in Django REST framework

python

django

django-rest-framework