python drf 序列化器之数据的增删改查（详细）

#url.py
​
from django.contrib import admin
from django.urls import path, re_path
from app_drf_books import views
​
urlpatterns = [
    path('admin/', admin.site.urls),
    path('books/', views.BooksAPIView.as_view()),
    re_path('books/(?P<pk>\d+)', views.BookAPIView.as_view())
]
​
#utils.py 自定义工具类
class MyResponse():
    def __init__(self):
        self.code = 100
        self.msg = 'OK'
​
    @property
    def dict(self):
        return self.__dict__
​
#模型类models.py
from django.db import models
​
​
# Create your models here.
​
​
class Books(models.Model):
    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    author = models.CharField(max_length=32)
    publish = models.CharField(max_length=32)
    
#ser.py 序列化器
from rest_framework import serializers
from app_drf_books import models
from rest_framework.exceptions import ValidationError
​
​
class BookSerializers(serializers.Serializer):
    id = serializers.CharField(read_only=True)
    title = serializers.CharField()
    price = serializers.CharField()
    author = serializers.CharField()
    publish = serializers.CharField()
​
    def update(self, instance, validated_data):
        instance.title = validated_data.get('title')
        instance.price = validated_data.get('price')
        instance.author = validated_data.get('author')
        instance.publish = validated_data.get('publish')
        instance.save()
        return instance
​
    def create(self, validated_data):
        result = models.Books.objects.create(**validated_data)
        return result
​
    def validate_title(self, data):
        if 'small baby' in data:
            raise ValidationError('书名中不能有敏感字眼哦')
        else:
            return data
​
    def validate_price(self, data):
        if float(data) >= 200:
            raise ValidationError('奸商啊，卖那么贵，不让你卖，气死你')
        else:
            return data
​
#view.py 视图函数，CBV模式
from rest_framework.views import APIView
from app_drf_books import models
from app_drf_books.ser import BookSerializers
from app_drf_books import utils
from rest_framework.response import Response
​
​
# Create your views here.
​
​
# 单本书籍的查，改，删
class BookAPIView(APIView):
    def get(self, request, pk):  # 单本书籍的查询
        response_dic = utils.MyResponse()  # 实例化自定义工具类中的response类
        book = models.Books.objects.filter(pk=pk).first()  # 获取当前查询图书对象
        book_ser = BookSerializers(instance=book)  # 实例化自定义序列化器
        response_dic.data = book_ser.data  # 将数据传入
        return Response(response_dic.dict)
​
    def put(self, request, pk):  # 单本书籍的修改
        response_dic = utils.MyResponse()  # 实例化自定义类
        book = models.Books.objects.filter(pk=pk).first()  # 获取要修改的书籍
        book_ser = BookSerializers(instance=book, data=request.data)  # 传入要修改的对象和数据
        if book_ser.is_valid():  # 校验数据
            book_ser.save()  # 保存数据，需要在自定义序列化器中重写update方法
            response_dic.data = book_ser.data
        else:
            response_dic.code = 99
            response_dic.msg = '校验不通过'
            response_dic.data = book_ser.errors  # 返回校验结果
        return Response(response_dic.dict)
​
    def delete(self, request, pk):  # 删除指定图书
        response_dic = utils.MyResponse()
        models.Books.objects.filter(pk=pk).delete()
        return Response(response_dic.dict)
​
​
# 查询全部书籍、增加新书籍
class BooksAPIView(APIView):
    def get(self, request):
        response_dic = utils.MyResponse()
        book = models.Books.objects.all()  # 获得全部book对象
        book_ser = BookSerializers(instance=book, many=True)  # 序列化多条数据需要加上many参数
        response_dic.data = book_ser.data
        return Response(response_dic.dict)
​
    def post(self, request):
        response_dic = utils.MyResponse()
        book_ser = BookSerializers(data=request.data)  # 新增时不需要传入修改对象，传入新增数据
        if book_ser.is_valid():  # 校验
            book_ser.save()
            response_dic.data = book_ser.data
        else:
            response_dic.code = 99
            response_dic.msg = '校验失败'
            response_dic.data = book_ser.errors
        return Response(response_dic.dict)
​