restful api 回顾

回顾一 APIView

首先说一下序列化 serializers

class UserModelSerializer(serializers.Serializer):
    key = serializers.CharField()
    cos_path = serializers.CharField()

# 对于这样的序列化，我们有几个字段就写几个字段--只能序列化和表单验证  不能存数据库里

class UserModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.UserInfo
        fields = "__all__"
# 对于这样的序列化，可以通过serializer对象 点 save 保存到数据库里

# 对于POST 请求
from rest_framework.response import Response
from rest_framework import serializers

class UserModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.UserInfo
        fields = "__all__"

class UserView(APIView):def post(self,request,*args,**kwargs):
　　　　# 序列化做校验
        ser = UserModelSerializer(data=request.data)
        if ser.is_valid():
　　　　　　　# 存入数据库的两种形式 ser.save(添加额外的值)
            # models.UserInfo.objects.create(**ser.validated_data)
            ser.save(user_id=1)
            return Response(ser.data)
        return Response(ser.errors)

# GET请求


class UserModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.UserInfo
        fields = "__all__"

class UserView(APIView):

    def get(self,request,*args,**kwargs):
        user_list = models.UserInfo.objects.all()
　　　　　# 做校验 这里的user_list 是多条要用下面的形式 要是单条的 要写成 mang=False  局部更新的话 添加一个 partial=True
        ser = UserModelSerializer(instance=user_list,many=True)
        return Response(ser.data)

回顾二 ListAPIView / CreateAPIView

1. CreateAPIView

class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"

class NewTestView(CreateAPIView):
    serializer_class = NewTestModelSerializer

# 直接添加就完事了
---------------------------------------------------------------
如果我们在添加前面干点事的话 重写post方法
class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"

class NewTestView(CreateAPIView):
    def post(self,request,*args,**kwargs):
　　　　print(123)
　　　　return super().post(self,request,*args,**kwargs)

对于自己要多存一个值到数据库

# 解释见下图
class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"

class NewTestView(CreateAPIView,ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.News.objects.filter(id__gt=4)

    def perform_create(self, serializer):
        serializer.save(uid=str(uuid.uuid4()))

对于用于只展示几个字段的需求

class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = ["id","name","age"]

2. ListAPIView 

class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"

class NewTestView(ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.News.objects.filter(id__gt=4)      

 # 对于 ListAPIView 需要一个 查出来的数据 queryset

补充一 fields和exclude的区别

通过fields和exclude定制页面展示数据。

需求：只显示用户表的id,name,age的数据，其他不显示。

class NewTestModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.News
        # fields = ["id","name",'age']    # 只展示这三个字段
        # fields = "__all__"　　　　　　　   # 展示所有的字段
        exclude = ['gender']              # 不展示这个字段

class NewTestView(ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.User.objects.all()

需求：数据库有5个字段，显示6个字段

两种方式  我分开写

class NewTestModelSerializer(serializers.ModelSerializer):

    xx = serializers.CharField(source='id')
class Meta:
        model = models.News
        fields = "__all__"
        # fields = ['id','name','age','gender','phone','xx',]
class NewTestView(ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.User.objects.all()


 最后形式    
[
    {id:1,name:'xxx',age:18...   xx:1},
    {id:2,name:'xxx',age:11...   xx:2},
    {id:3,name:'xxx',age:99,     xx:3},
]

方式二

class NewTestModelSerializer(serializers.ModelSerializer):
    x1 = serializers.SerializerMethodField()
    class Meta:
        model = models.News
        fields = "__all__"
        # fields = ['id','name','age','gender','phone','x1']

    
    def get_x1(self,obj):
        return obj.id
    
class NewTestView(ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.User.objects.all()
    
最后形式
[
    {id:1,name:'xxx',age:18...   x1:1},
    {id:2,name:'xxx',age:11...   x1:2},
    {id:3,name:'xxx',age:99,     x1:3},
]

补充二 read_only

添加时不要，查看时候需要

需求：编写两个接口 添加（3字段）、获取列表（5个字段）

两种形式 看标颜色的地方
class NewTestModelSerializer(serializers.ModelSerializer):
    # phone = serializers.CharField(source='phone',read_only=True)
    # email = serializers.CharField(source='email',read_only=True)
    class Meta:
        model = models.News
        fields = "__all__"
        read_only_fields = ['phone','email',]
        
class NewTestView(CreateAPIView, ListAPIView):
    serializer_class = NewTestModelSerializer
    queryset = models.User.objects.all()
    
形式
添加：
    {
        name:'xx',
        age:'19',
        gender:1
    }
获取：
    [
        {name:'xx',age:'xx',gender:'',phone:'xx',email:xxx}
    ]

补充三 复杂需求

添加时用一个serializers、列表时用一个serializers

class NewTestModelSerializer1(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"
        
class NewTestModelSerializer2(serializers.ModelSerializer):
    class Meta:
        model = models.News
        fields = "__all__"

class NewTestView(CreateAPIView, ListAPIView):
    queryset = models.User.objects.all()
    
    def get_serializer_class(self):
        if self.request.method == 'POST':
            return NewTestModelSerializer1
        if self.request.method == 'GET':
            return NewTestModelSerializer2

补充四serializers嵌套

{
    "cover":"https://123.png",
    "content":"学习xuexi",
    "address":"北京",
    "topic":"1",
    "imageList":[
        
        {
            "key":"123.png",
            "cos_path":"https://12344"
        },
                {
            "key":"123.png",
            "cos_path":"https://12344"
        }
        ]
}

我们有一段数据，下面的代码中  CreateNewsModelSerializer 校验了第一层数据  第二层的imageList数据没法校验 用 CreateNewsTopicModelSerializer 来校验

class CreateNewsTopicModelSerializer(serializers.Serializer):
　　"""imageList的数据必须是这两个字段"""
    key = serializers.CharField()
    cos_path = serializers.CharField()


class CreateNewsModelSerializer(serializers.ModelSerializer):
    imageList = CreateNewsTopicModelSerializer(many=True)

    class Meta:
        model = models.News
        exclude = ['user', 'viewer_count', 'comment_count',"favor_count"]

    def create(self, validated_data):
        # 把imageList切走
        image_list = validated_data.pop('imageList')

        # 创建New表中的数据
        news_object = models.News.objects.create(**validated_data)

        data_list = models.NewsDetail.objects.bulk_create(
            [models.NewsDetail(**info, news=news_object) for info in image_list]
        )
        news_object.imageList = data_list

        if news_object.topic:
            news_object.topic.count += 1
            news_object.save()

        return news_object

class NewsView(CreateAPIView):
    """
    发布动态
    """
    serializer_class = CreateNewsModelSerializer
    def perform_create(self, serializer):
        # 只能保存：News表中的数据（）
        # 调用serializer对象的save（先调用create）
        new_object = serializer.save(user_id=1)
        return new_object