drf 三级菜单后台序列化以及数据库的设计

第一种，

model.py结构：

class GoodsCategory(models.Model):
    """
    商品类别
    """
    CATEGORY_TYPE = (
        (1, "一级类目"),
        (2, "二级类目"),
        (3, "三级类目"),
    )
    name = models.CharField(default="", max_length=30, verbose_name="类别名", help_text="类别名")
    code = models.CharField(default="", max_length=30, verbose_name="类别code", help_text="类别code")
    desc = models.TextField(default="", verbose_name="类别描述", help_text="类别描述")
    category_type = models.IntegerField(choices=CATEGORY_TYPE, verbose_name="类目级别", help_text="类目级别")
    parent_category = models.ForeignKey("self", null=True, blank=True, verbose_name="父类目级别", help_text="父目录",
                                        related_name="sub_cat")

看下这个视图设置，

class CategoryView(ListAPIView):
    '''
    全部分类
    '''
    queryset = GoodsCategory.objects.filter(category_type=1)
    serializer_class = CategorySerializer

第二种：

也可以这样设计数据库：

class GoodsCategory(BaseModel):
 # """
 # 商品类别
 # """
    name = models.CharField(max_length=10, verbose_name='名称')
    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.CASCADE, verbose_name='⽗类别',related_name='sub_cat')
    class Meta:
        db_table = 'tb_goods_category'
        verbose_name = '商品类别'
        verbose_name_plural = verbose_name
    def __str__(self):
        return self.name

视图这样写：

class CategoryInfoView(mixins.ListModelMixin,GenericAPIView):
    queryset = GoodsCategory.objects.filter(parent=None)
    serializer_class = CategorySerializer
    def get(self,request):
        return self.list(request)

因为第一级目录的父级是None,然后以这个为条件实现查询，有点像三级联动数据库的设计

序列化实现充分用的是数据库反查,related_name设置。

from rest_framework import serializers
from .models import GoodsCategory

class CategorySerializer3(serializers.ModelSerializer):
    class Meta:
        model = GoodsCategory
        fields = "__all__"

class CategorySerializer2(serializers.ModelSerializer):
    sub_cat = CategorySerializer3(many=True)
    class Meta:
        model = GoodsCategory
        fields = "__all__"

class CategorySerializer(serializers.ModelSerializer):
    sub_cat = CategorySerializer2(many=True)
    class Meta:
        model = GoodsCategory
        fields = "__all__"

数据结构如下展示：