Django 第六章RESTFramework(DRF)进阶篇(APIView类)

1. DRF序列化器：关联表显示

应用场景：

一对多：一个项目有多个应用，一个应用只能属于一个项目
多对多：一个应用部署到多台服务器，一个服务器部署多个应用

1.1 定义数据模型

class Project(models.Model):
    name = models.CharField(max_length=30)

class App(models.Model):
    name =models.CharField(max_length=30)
    Project = models.ForeignKey(Project,on_delete=models.CASCADE)  #一对多ForeignKey

class Server(models.Model):
    hostname = models.CharField(max_length=30)
    ip = models.GenericIPAddressField()
    app = models.ManyToManyField(App)   #多对多ManyToManyField

1.2 定义路由

re_path('^api/project/$', views.ProjectView.as_view()),
re_path('api/app/$',views.Appview.as_view()),
re_path('^api/server/$',views.ServerView.as_view()),

1.3 定义序列化器(serializers.py)

from  myapp_api.models import User
from myapp_api.models import Project, App, Server
from rest_framework import serializers

class  UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = "__all__"
        extra_kwargs = {
    
    
            'name': {
    
    'max_length':2, 'required':True}, #限制名字长度
            'age':{
    
    'min_value':16,'max_value':100,'required':True}  #限制年龄
        }


class ProjectSerializer(serializers.ModelSerializer):
    class   Meta:
        model = Project
        fields = "__all__"

class AppSerializer(serializers.ModelSerializer):
    class Meta:
        model = App
        fields = "__all__"

class ServerSerializer(serializers.ModelSerializer):
    class Meta:
        model = Server
        fields = "__all__"

1.4 定义视图(views)

from  rest_framework.views  import APIView
from rest_framework.response import Response
from .serializers import UserSerializer, ProjectSerializer,AppSerializer,ServerSerializer
from myapp_api.models import User, Project, App, Server


class Appview(APIView):
    def get(self, request, id=None):
        if id:
            obj = App.objects.get(id=id)
            ser = AppSerializer(obj)
        else:
            queryset = App.objects.all()
            ser = AppSerializer(queryset, many=True)
        res = {
    
    'code': 200, 'msg': '获取成功', 'data': ser.data}
        return Response(res)
    def post(self,request):
        ser = AppSerializer(data=request.data)
        ser.is_valid(raise_exception=True)
        ser.save()
        res = {
    
    'code': 200, 'msg': '创建用户成功'}
        return Response(res)


class ServerView(APIView):
    def get(self, request, id=None):
        if id:
            obj = Server.objects.get(id=id)
            ser = ServerSerializer(obj)
        else:
            queryset = Server.objects.all()
            ser = ServerSerializer(queryset, many=True)
        res = {
    
    'code': 200, 'msg': '获取成功', 'data': ser.data}
        return Response(res)
    def post(self,request):
        ser = ServerSerializer(data=request.data)
        ser.is_valid(raise_exception=True)
        ser.save()
        res = {
    
    'code': 200, 'msg': '创建用户成功'}
        return Response(res)

1.5添加数据



project/app/server/分别可以成功添加数据

2.0 DRF 序列化器：关联表显示

序列化器返回时当前模型中的字段，如果字段时外键时，返回是外键对应id,如果想要显示外键对应的详细信息做法如下

3.0 DRF序列化器 SerializerMethodFuekd

统计该项目应用个数

DRF 序列化器： 改变序列化和反序列化的行为

4.0 Request与Response

DRF传入视图的request对象不再是Django默认的HttpRequest对象，而是基于HttpRequest类扩展后的Request类的对象，Request对象的数据是自动根据前端发送的数据同意解析数据格式
常用属性：

request.data: 返回post提交的数据，与request.post类似
request.query_params：返回GET URL 参数，与request.GET类似