如何通过Django中的外国键将父表个体与新的子表实例相关联？

Question

我是Django和ReactJ的新手。我正在创建具有Django模型中外键关系的模型。但是，当我将数据发送到我的Django REST API时，它会根据外键值创建父表对象，而不是将其与现有值相关联。我如何与新创建的儿童实例相关联而不是创建父对象？

我正在寻找过去的两天，但对我没有任何帮助。我在做什么错？

它为我的ReactJS应用程序提供了此响应标题：

{“ store_title”：[“已经存在此商店标题的数据。”]}

数据

def user_directory_path(instance, filename):
  
    # file will be uploaded to MEDIA_ROOT / user_<id>/<filename>
    return 'user_{0}/{1}'.format(instance.user, filename)

class StoreData(models.Model):
    STATUS=(
        ('A','Active'),
        ('P','Pending approval'),
        ('B','Blocked'),
    )
    
    store_title=models.CharField(max_length=50,primary_key=True, null=False)
    tagline=models.CharField(max_length=100,null=False, default='')
    store_type=models.CharField(max_length=10,null=False, default='')
    description=models.CharField(max_length=500,null=False, default='')
    user=models.ForeignKey(User,on_delete=models.CASCADE,null=True)
    logo_img=models.ImageField(upload_to=user_directory_path, default='')
    brand_img=models.ImageField(upload_to=user_directory_path, default='')
    link=models.CharField(max_length=100, default='')
    date_created=models.DateField(default=timezone.now)
    status=models.CharField(max_length=20,choices=STATUS,default='A')
    def __str__(self):
        return str(self.store_title)

class Categories(models.Model):
    title=models.CharField(max_length=50, default='none')
    thumbnail_img=models.ImageField(upload_to=user_directory_path, default="")
    store_title=models.ForeignKey(StoreData, on_delete=models.CASCADE, default='')
    def __str__(self):
        return str(self.title)

。

class StoreSerializer(serializers.ModelSerializer):
    class Meta:
        model = StoreData
        fields = '__all__'


class CategorySerializer(serializers.ModelSerializer):
    def __init__(self, data):
        self.store_title=serializers.SlugRelatedField(queryset=StoreData.objects.filter(pk=data['store_title']))
        
    class Meta:
        model = Categories
        fields = '__all__'

“

@api_view(['POST'])
def addCategory(request):
    serializer=CategorySerializer(data=request.data)
    if serializer.is_valid():
        serializer.save()
        return Response("success", status.HTTP_200_OK)
    else:
        return Response(serializer.errors,status.HTTP_405_METHOD_NOT_ALLOWED)

{

function handleSubmit(e) {
        e.preventDefault()
        let category_data = new FormData()
        category_data.append('title', title)
        category_data.append('thumbnail_img', selectedThumb_Img)
        category_data.append('store_title', JSON.parse(localStorage.getItem('store_data')).title)

        fetch('http://localhost:8000/store_apis/addCategory/', {
            method: 'Post',
            body: category_data
        })
            .then(res => {
                if (res.status !== 200)
                    document.getElementById('text-error').innerHTML = res.Text
                else {
                    navigate('/categories')
                }
            })
            .catch((res) => document.getElementById('text-error').innerHTML = res.statusText)

    }

store_title” ： 现有带有新创建的儿童实例的父型实例？

谢谢