DRF 一对多序列化与反序列化

DRF 一对多序列化与反序列化

• 序列化

  出库的过程，是从数据库中把数据读出并以json的形式供前端使用

• 反序列化

  入库的过程，是从前端将数据传入到views.py的函数或者类中，经过后台逻辑处理，最终写到数据库中。

• 安装 djangorestframework

  pip install djangorestframework

• 注册到INSTALL_APPS中

  INSTALLED_APPS = [
      ...
      'rest_framework',
  ]

• 配置数据库

  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.mysql',
          'NAME': 'tutorial',
          'HOST': '127.0.0.1',
          'PORT': 3306,
          'USER': 'root',
          'PASSWORD': 'ocnt-123',
          'OPTIONS':{
                  "init_command":"SET foreign_key_checks = 0;",# 禁用外键约束
          }
      }
  }

• 新增老师类和学生类

from django.db import models

# 创建老师模型
class Teacher(models.Model):
    # 教师名称
    name = models.CharField(max_length=32,unique=True)
    # 添加时间
    addtime = models.DateTimeField(auto_now_add=True)

    class Meta:
        # 指定表名
        db_table = 'teacher'


# 创建学生模型,一个学生只能选择一个老师
class Student(models.Model):
    # 学生名称
    name = models.CharField(max_length=32,unique=True)
    # 添加时间
    addtime = models.DateTimeField(auto_now_add=True)
    # 外键 与Teacher类绑定
    teacher = models.ForeignKey('Teacher',on_delete=models.CASCADE)

    class Meta:
        # 指定表名
        db_table = 'student'

• 新增视图函数类 TeacherView

  from rest_framework.views import  APIView
  from rest_framework.response import Response
  from .serializers import TeacherSerializer,StudentSerializer
  from . import models
  
  # 创建用户视图类
  class TeacherView(APIView):
      # 获取用户信息
      def get(self,request):
          data = models.Teacher.objects.all()
          info = TeacherSerializer(data,many=True)
          return Response({
              "status":200,
              "msg":"",
              "data":info.data
          })
  
  
  
      # 添加用户
      def post(self,request):
          data = request.data
          flag = models.Teacher.objects.create(**data)
          if not flag:
              return Response({"status":201,"msg":"添加数据失败","data":[]})
          return Response({"status":200,"msg":"","data":[]})
  
  
  
      # 编辑用户
      def put(self,request):
          id = request.data.pop("id")
          flag = models.Teacher.objects.filter(id=id).update(**request.data)
          if not flag:
              return Response({
                  "status":201,
                  "msg":"编辑失败",
                  "data":[]
              })
          return Response({
              "status":200,
              "msg":"编辑成功",
              "data":""
          })
  
  
      # 删除用户
      def delete(self,request):
          id = request.data.pop('id')
          teacher = models.Teacher.objects.filter(id=id).delete()
          if not teacher[0]:
              return Response({
                  "status": 201,
                  "msg": "删除失败",
                  "data": []
              })
          return Response({
              "status": 200,
              "msg": "删除成功",
              "data": ""
          })
  

  • 新增视图函数类 StudentView

  # 学生视图
  class StudentView(APIView):
      # 获取数据
      def get(self,request):
          data = models.Student.objects.all()
          info = StudentSerializer(data,many=True)
  
          return Response({
              "status":200,
              "msg":"",
              "data":info.data
          })
  
      # 添加数据
      def post(self,request):
          data = request.data
          flag = models.Student.objects.create(**data)
          if not flag:
              return Response({
                  "status":201,
                  "msg":"学生添加失败",
                  "data":[]
              })
          return Response({
              "status":200,
              "msg":"学生添加成功",
              "data":[]
          })
  
  
      # 编辑数据
      def put(self,request):
          id = request.data.pop('id')
          flag = models.Student.objects.filter(id=id).update(**request.data)
          if not flag:
              return Response({
                  "status":201,
                  "msg":"数据编辑失败",
                  "data":[]
              })
          return Response({
              "status":200,
              "msg":"数据编辑成功",
              "data":[]
          })
  
      # 删除数据
      def delete(self,request):
          id = request.data.get('id')
          student = models.Student.objects.filter(id=id).delete()
          if not student[0]:
              return Response({
                  "status":201,
                  "msg":"删除失败",
                  "data":[]
              })
          return Response({
              "status":200,
              "msg":"删除成功",
              "data":[]
          })
  

• 序列化类 serializers.py

  from rest_framework import serializers
  from . import models
  
  # 老师数据序列化
  class TeacherSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Teacher
          fields = '__all__'
  
  
  # 学生数据序列化
  class StudentSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Student
          fields = '__all__'
  

• 二级路由 urls.py

  from django.urls import path
  from . import views
  urlpatterns = [
      path('teacher/',views.TeacherView.as_view()),
      path('student/',views.StudentView.as_view()),
  ]

• 访问地址

  • GET http://127.0.0.1:8000/snippets/teacher/
    
  • POST http://127.0.0.1:8000/snippets/teacher/
    
  • PUT http://127.0.0.1:8000/snippets/teacher/
    

  • DELETE http://127.0.0.1:8000/snippets/teacher/
    

  • GET http://127.0.0.1:8000/snippets/student/
    
  • POST http://127.0.0.1:8000/snippets/student/
    
  • PUT http://127.0.0.1:8000/snippets/student/
    

  • DELETE http://127.0.0.1:8000/snippets/student/
    

• 获取老师名下有多少个学生

  • serializers.py

    from rest_framework import serializers
    from . import models
    
    # 学生数据序列化
    class StudentSerializer(serializers.ModelSerializer):
        class Meta:
            model = models.Student
            fields = '__all__'
    
    
    # 老师数据序列化
    class TeacherSerializer(serializers.Serializer):
        id = serializers.IntegerField()
        name = serializers.CharField(max_length=32)
        student_set = StudentSerializer(many=True,read_only=True)

  • 调用此地址 GET http://127.0.0.1:8000/snippets/teacher/
    

• 获取学生的老师是谁？

  • serializers.py

    from rest_framework import serializers
    from . import models
    
    # 学生数据序列化
    class StudentSerializer(serializers.ModelSerializer):
        teacherName = serializers.CharField(source='teacher.name')
        class Meta:
            model = models.Student
            fields = ('id','name','teacherName')
    
    
    # 老师数据序列化
    class TeacherSerializer(serializers.Serializer):
        id = serializers.IntegerField()
        name = serializers.CharField(max_length=32)
        student_set = StudentSerializer(many=True,read_only=True)

  • 调用此地址 GET http://127.0.0.1:8000/snippets/teacher/