序列化，反序列化

from django.shortcuts import render,HttpResponse

# Create your views here.
from rest_framework.views import APIView
from app01 import models
from rest_framework.serializers import Serializer


from rest_framework.response import  Response
from django.core import serializers
# 把对象转换成json格式字符串
from app01.app01serializer import BookSerializer
class Books(APIView):
    def get(self,request):
        response={‘code‘:100,‘msg‘:‘查询成功‘}
        books=models.Book.objects.all()
        #了解
        # ret = serializers.serialize("json", books)
        #如果序列化多条，many=True（也就是queryset对象，就需要写）
        #如果序列化一条（可以不写）就是一个book对象,instance是要序列化的对象
        bookser=BookSerializer(instance=books,many=True)
        # print(type(bookser.data))
        # bookser.data 是一个returnList的类型
        response[‘data‘]=bookser.data
        return Response(response) #response可以放returnlist也就是列表，也可以是字典，就是不能是对象
    #使用继承了Serializers序列化类的对象，反序列化
    # def post(self,request):
    #     #实例化产生一个序列化类的对象，data是要反序列化的字典
    #     # print(request.data)
    #     bookser=BookSerializer(data=request.data)
    #     if bookser.is_valid():
    #         #清洗通过的数据
    #         ret=bookser.create(bookser.validated_data)
    #
    #     return Response()
    #使用继承了ModelSerializers序列化类的对象，反序列化
    def post(self,request):
        #实例化产生一个序列化类的对象，data是要反序列化的字典
        bookser=BookSerializer(data=request.data)
        # bookser.data
        if bookser.is_valid(raise_exception=True):
            #清洗通过的数据
            bookser.save()
        else:
            print(bookser.errors[‘name‘][0])
        return Response()

from app01 import models
from rest_framework import serializers
class AuthorSerializer(serializers.Serializer):
    name=serializers.CharField()
    age=serializers.CharField()
# class BookSerializer(serializers.Serializer):
#     #指定source=‘name‘ ，表示序列化模型表中的name字段，重名命为name5（name和source=‘name‘指定的name不能重名）
#     name5=serializers.CharField(source=‘name‘)
#     #write_only 序列化的时候，该字段不显示
#     #read_only 反序列化的时候，该字段不传
#     price=serializers.CharField(write_only=True)
#     #如果要取 出版社的city source=‘publish.city‘
    publish=serializers.CharField(source=‘publish.name‘)
#     #source不但可以指定一个字段，还可以指定一个方法
#     book_type = serializers.CharField(source=‘get_xx_display‘,read_only=True)
#     #序列化出版社的详情,指定SerializerMethodField之后，可以对应一个方法，返回什么内容，publish_detail就是什么内容
    publish_detail=serializers.SerializerMethodField(read_only=True)
#     #对应的方法固定写法get_字段名
#     def get_publish_detail(self,obj):
#         # print(type(obj))
#         return {‘name‘:obj.publish.name,‘city‘:obj.publish.city}
#
#     #返回所有作者信息
    authors=serializers.SerializerMethodField(read_only=True)
#     def get_authors(self,obj):
#         # return [ {‘name‘:author.name,‘age‘:author.age} for author in obj.authors.all()]
#         authorser=AuthorSerializer(obj.authors.all(),many=True)
#         return authorser.data
#
#     def create(self, validated_data):
#         ret=models.Book.objects.create(**validated_data)
#         return ret
from rest_framework import exceptions
from app01 import models

class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model=models.Book
        # fields=(‘nid‘,‘name‘)
        #不能跟fields同时使用
        # exclude=[‘name‘,]
        fields=(‘__all__‘)
        #深度是1，官方建议不要超过10，个人建议不要超过3
        # depth=1
    # xx=serializers.CharField(source=‘get_xx_display‘)
    # authors=serializers.SerializerMethodField()
    # def get_authors(self,obj):
    #     ret=AuthorSerializer(instance=obj.authors.all(),many=True)
    #     return ret.data
    # name=serializers.CharField()
    #反序列化的校验（局部校验，全局校验）
    def validate_name(self,value):

        print(value)
        raise exceptions.ValidationError(‘不能以sb开头‘)
        # if value.startswith(‘sb‘):
        #     raise ValidationError(‘不能以sb开头‘)
        # return value

    def validate(self,attrs):
        print(attrs)
        # if attrs.get(‘price‘)!=attrs.get(‘xx‘):
        #     raise exceptions.ValidationError(‘name和price相等，不正常‘)
        return attrs

from django.db import models

# Create your models here.
class Book(models.Model):
    nid = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    publish_date = models.DateField(null=True)
    xx=models.IntegerField(choices=((0,‘文学类‘),(1,‘情感类‘)),default=1,null=True)
    publish = models.ForeignKey(to=‘Publish‘,to_field=‘nid‘,on_delete=models.CASCADE,null=True)
    authors=models.ManyToManyField(to=‘Author‘)
    def __str__(self):
        return self.name
    def test(self):
        return ‘xxx‘


class Author(models.Model):
    nid = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32)
    age = models.IntegerField()



class Publish(models.Model):
    nid = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=32)
    email = models.EmailField()

    def __str__(self):
        return self.name