第十一单元 序列化器

1. 增删改查 *** 作

1. *** 作有5个：
   增加一个数据post，删除一个数据delete，查询所有数据get，查询一个数据get，修改一个数据put
2. 有些需要参数、而有些不需要参数
   不需要参数：增加一个数据post,查询所有数据get 静态路由
   需要参数：删除一个数据delete，查询一个数据get，修改一个数据put 带id的动态路由
3. 只需要2个视图就可已完成

2. 查看所有数据和曾加数据

1. 首先在子应用里创建一个serializers.py文件，编写序列化器

from rest_framework import serializers
class PeopleSerializer(serializers.Serializer):
    # id = serializers.IntegerField()
    name = serializers.CharField(max_length=20)
    age = serializers.IntegerField()
    sex = serializers.CharField(max_length=20)

2. 图层写入方法

from rest_framework.views import APIView
from rest_framework.response import Response
from myapp.models import People
from myapp.serializers import PeopleSerializer
# 查看所有信息
class PeopleView(APIView):
	def get(self, request):
		people_data = People.objects.all()
		ser = PeopleSerializer(people_data, many=True)
		# .data必须加		status=200 返回状态码
		return Response(ser.data, status=200)
	# 增加数据
	def post(self, request):
		ser = PeopleSerializer(data=request.data)
		# 判断是否报错
		if ser.is_valid(raise_exception=True):
			# 保存
			ser.save()
			return Response({'mag': 'success'}, status=201)
		return Response({'msf': 'error'}, status=400)

3. 增加数据还需要在serializers文件内写入方法

    def create(self, validated_data):
        obj = People.objects.create(
            **validated_data
        )
        return obj

4. 编写静态路由

path('peo/', views.PeopleView.as_view()),

3. 查看一个信息、修改数据和删除数据

1. 编写动态视图

class Peopleviews2(APIView):
    # 获取一个数据
    def get(self, request, id):
        try:
            peo_data = People.objects.get(id=id)
        except Exception as a:
            print(a)
            return Response({'msg': 'error'}, status=404)
        ser = PeopleSerializer(peo_data)
        return Response(ser.data, status=200)
    # 修改数据
    def put(self, request, id):
        try:
            upd_data = People.objects.get(id=id)
        except Exception as a:
            print(a)
            return Response({'msg': 'error'}, status=400)
        ser = PeopleSerializer(instance=upd_data, data=request.data)
        if ser.is_valid(raise_exception=True):
            ser.save()
            return Response({"msg": 'success'}, status=201)
        return Response({'msg': 'error'}, status=400)
    # 删除数据
    def delete(self, request, id):
        try:
            del_data = People.objects.get(id=id)
        except Exception as a:
            print(a)
            return Response({'msg': 'error'}, status=400)
        del_data.delete()
        return Response({'msg': 'success'}, status=204)

2. 修改数据还需要在serializers文件内写入方法

    def update(self, instance, validated_data):
        instance.name = validated_data.get('name')
        instance.age = validated_data.get('age')
        instance.sex = validated_data.get('sex')
        instance.save()
        return instance

3. 编写动态路由

path('peo//', views.Peopleviews2.as_view())

4. 模型序列化器

class PeopleSerializer2(serializers.ModelSerializer):
    class Meta:
        model = People
        fields = '__all__'

在serializers文件中定义了序列化器后就不用定义之前的方法了

5. 模型序列化器配置

class GoodsSer(serializers.ModelSerializer):
    class Meta:
        model = Goods
        fields = '__all__' # 指明所有模型类字段
        # exclude = ('createtime',) # 排除掉的字段
        # read_only_fields = ('title','description') # 只用于序列化的字段
        # fields = ('title','description','inventory') # 手动指明字段
        # extra_kwargs = {
        #     'price':{'min_value':0, 'required':True},
        # } # 修改原有字段的选项参数