1. 什么是序列化,其实在python中我们就学了序列化工具json工具,就是吧信息存为类字典形式
2. DRF框架自带序列化的工具: serializers
3. DRF框架 serializers 分为:第一种 Serializer 第二种 ModelSerializer
第一种用法之 Serializer
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() publish = models.ForeignKey(to='Publish',to_field='nid',on_delete=models.CASCADE) authors=models.ManyToManyField(to='Author') def __str__(self): return self.name def test(self): #注意: 这里是给后面序列化组件的source指定方法用的 return str(self.price)+self.name class Author(models.Model): nid = models.AutoField(primary_key=True) name = models.CharField(max_length=32) age = models.IntegerField() author_detail = models.OneToOneField(to='AuthorDatail',to_field='nid',unique=True,on_delete=models.CASCADE) class AuthorDatail(models.Model): nid = models.AutoField(primary_key=True) telephone = models.BigIntegerField() birthday = models.DateField() addr = models.CharField(max_length=64) 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
from rest_framework import serializers from app.models import Book,Author ####################这里是serializers 实例化方法一的实现 # class Bookserializer(serializers.Serializer): # 这里是通过rest_framwork 来实例化对象中的内容,返回给前端的数据信息 id = serializers.CharField() # source指定数据库中的名字,前面可以自定义名字来使用,给前端显示的是自定义名字 bookname 是自己自定义的名字 bookname = serializers.CharField(source='name') price = serializers.CharField() # source还可以通过对象继续点其他属性, 可以跨表点其他的想要的属性(这个只是拿到publish的单个字段) publish_name = serializers.CharField(source='publish.name') #注意source 还可以调用models中 Book 表内的方法 maxprice = serializers.CharField(source='test') #注意,source 可以名字自定义显示,可以跨表链接其他想要的属性,还可以调用book表中的自定义的方法 # publish字段，返回出版社的所有信息，包括id，name，email。。。。 # #SerializerMethodField配合一个方法，方法的返回值会付给publish #SerializerMethodField 可以拿到跨表内的多个字段,你吧想要的都返还回去就行了(这里是拿到publish的多个字段信息) publish = serializers.SerializerMethodField() #这里这里的obj 是当前序列化的对象 这里的对象就是book!!!! def get_publish(self,obj): return {'id':obj.publish.pk, 'name': obj.publish.name,'city':obj.publish.city} ####################这里是serializers 实例化方法一的实现
第二种用法之ModelSerializer
###################这里是serializers实例化实现方法二 的实现,调用ModelSerializer class Bookserializer(serializers.ModelSerializer): #这里一个meta类去调用Book这个表 class Meta: model = models.Book #fields 是然他显示所有的内容,渲染出去 fields = "__all__" # '__all__' 是渲染全部出去 # #fields = ['id', 'name'] # ['....'] 是渲染指定的 # # exclude=['name'] #是除了name 之外的全部都渲染出去,不能和fields同时出现 # #depth = 3 #深度 ,官方建议最多写10,深度显示所有的表 # #这里是可以自定义,自定义显示publish的名字, publish_name = serializers.CharField(source='publish.name') publish = serializers.SerializerMethodField() #也可以拿到publish的多个字段信息 def get_publish(self,obj): return {'id':obj.publish.pk, 'name':obj.publish.name} ###################这里是serializers实例化实现方法二 的实现,调用ModelSerializer 最后建议使用serializers.ModelSerializer 来实现序列化 ,因为在修改接口和添加接口 对save() 有很好的依赖关系
# 局部钩子函数，对单个字段校验 #校验name字段不能以sb开头 def validate_name(self,value): if value.startswith('sb'): #不能让你过 raise ValidationError('书名不能以sb开头') else: return value #全局钩子函数，对全局字段进行校验 # def validate(self,a): # # print(a) # name=a.get('name') # price=a.get('price') # if name != price: # raise ValidationError('错了') # else: # return a
最后视图函数调用序列化的内容并返回给前端进行渲染处理
在View视图层操作: 查询多本书的方法: from rest_framework.views import APIView from rest_framework.response import Response from app.models import Book from app.Myserialize import Bookserializer class Books(APIView): # 这个是获取多本书的接口 def get(self, request, *args, **kwargs): # 这里是通过对drf框架 使用cbv 的get请求 response = {'status': 100, 'msg': '获取成功'} # 设置发送出去response 信息 book_list = Book.objects.all() book_ser = Bookserializer(book_list, many=True) # 使用drf 实例化 自定义的Bookserializer 来实例化 response['data'] = book_ser.data # 把实例化book_ser 的data数据放入 response['data']中 return Response(response) # 在使用Response来返回出去 def post(self, request): #这个是添加书的接口 response = {'status': 100, 'msg': '添加成功'} try: book_ser = Bookserializer(data=request.data) if book_ser.is_valid(): #这里就是晕倒的反序列的内部工具和钩子判断 book_ser.save() response['data'] = book_ser.data #判断通过吧数据返回出去 else: response['msg'] = book_ser.errors except Exception as e: response['msg'] = str(e) return Response(response)
class BookView(APIView): #获取单本图书的接口 def get(self, request, pk,*args, **kwargs): response = {'status': 100, 'msg': '获取成功'} #取到pk为传入的pk的书，book对象 book = models.Book.objects.all().filter(pk=pk).first() #要序列化单条，many=False book_ser=BookSerializer(instance=book,many=False) # book_ser=BookSerializer(book,many=False) response['data']=book_ser.data return Response(response) def put(self,request,pk): #修改某本书 response = {'status': 100, 'msg': '修改'} book=models.Book.objects.filter(pk=pk).first() #修改 book_ser = BookSerializer(instance=book,data=request.data) if book_ser.is_valid(): book_ser.save() response['data']=book_ser.data else: response['msg']=book_ser.errors return Response(response)
在路由层的配置: urlpatterns = [ url(r'^admin/', admin.site.urls), url(r'^books/$', views.BooksView.as_view()), #查看全部书的接口 url(r'^books/(?P<pk>d+)', views.BookView.as_view()), #查看单个书的接口 ]
#总结,个人建议使用第二种序列化的方法,这样对反序列化有很好的帮助
以下是全部的接口信息 from app import models from app.Myserializers import BookSerializers # Create your views here. from rest_framework.views import APIView from rest_framework.response import Response class Booksview(APIView): def get(self,request,*args,**kwargs): #获取多本书 response = {'status':100, 'msg':'查询成功'} book_list = models.Book.objects.all() book_ser = BookSerializers(book_list,many=True) response['data'] = book_ser.data return Response(response) def post(self,request): #添加书 response = {'status':100, 'msg':'添加成功'} try: book_ser = BookSerializers(data=request.data) #序列化工具拿到的数据是在request.data内的字典中获取 if book_ser.is_valid(): #进行钩子判断与基础验证 book_ser.save() response['data'] =book_ser.data else: response['msg']= book_ser.errors except Exception as e: response['msg'] =str(e) return Response(response) class Bookview(APIView): def get(self, request, pk, *args, **kwargs): #获取单本书的接口 response = {'status':100 , 'msg': '获取成功'} book = models.Book.objects.all().filter(pk=pk).first() book_ser = BookSerializers(instance=book,many=False) response['data'] = book_ser.data return Response(response) def put(self, request,pk): #修改但本书的接口 response = {'status':100, 'msg':'修改成功'} book = models.Book.objects.filter(pk=pk).first() book_ser = BookSerializers(instance=book,data=request.data) if book_ser.is_valid(): book_ser.save() response['data']= book_ser.data else: response['msg']= book_ser.errors return Response(response) def delete(self,request,pk): #删除的接口 response = {'status':100, 'msg': '删除成功'} book = models.Book.objects.filter(pk=pk).delete() return Response(response)