一、序列化组件的作用
在前后端分离开发时，前端与后端用来交互的数据的格式是一致的（数据格式为字符串的json数据），于是后端程序员在传递数据时，便要将数据封装成符合格式的数据，如果不借助方法，手动进行数据封装，会非常的浪费时间，在Django rest framework中的序列化组件帮我们解决了这个问题。
二、Django自带的序列化组件
from django.core import serializers def test(request): book_list = Book.objects.all() ret = serializers.serialize("json", book_list) return HttpResponse(ret)
三、rest framework 序列化之Serializer
- models.py
from django.db import models # Create your models here. from django.db import models # Book书籍：id name price publish_date publish(publish_id) class Book(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=20) price = models.DecimalField(max_digits=5, decimal_places=2) publish_date = models.DateField() publish = models.ForeignKey(to='Publish', to_field='id', null=True, on_delete=models.SET_NULL, db_constraint=False) # 多对多关系字段，该字段不会再book表中形成字段，是用来创建关系表的 author = models.ManyToManyField(to='Author', db_constraint=False) def test(self): return 22 # AuthorDetail作者详情: id age telephone info class AuthorDetail(models.Model): id = models.AutoField(primary_key=True) age = models.IntegerField() telephone = models.BigIntegerField() # 存大文本 info = models.TextField() # Author作者：id name class Author(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=20) # author_detail = models.ForeignKey(to='AuthorDetail', to_field='id', unique=True) author_detail = models.OneToOneField(to='AuthorDetail', to_field='id', null=True, on_delete=models.SET_NULL, db_constraint=False) # Publish出版社：id name address class Publish(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=20) address = models.CharField(max_length=64)
- urls.py
from django.conf.urls import url from django.contrib import admin from app01.views import BooksView,BookView urlpatterns = [ url(r'^admin/', admin.site.urls), url(r'^Books/$', BooksView.as_view()), ]
- MySerializer.py
from rest_framework import serializers from rest_framework.exceptions import ValidationError class BookSerializers(serializers.Serializer): id = serializers.CharField() name = serializers.CharField() price = serializers.DecimalField(max_digits=5,decimal_places=2) publish_date = serializers.DateField() publish = serializers.CharField(source='publish.name') # author = serializers.CharField(source='author.all') #获取author对象，结果为 "author": "<QuerySet [<Author: Author object>]>" author = serializers.SerializerMethodField() def get_author(self,obj): author_list = [] for author in obj.author.all(): author_list.append({ "id":author.id, "name":author.name, "age":author.author_detail.age, "info":author.author_detail.info }) return author_list
注意：
source 如果是字段，会显示字段，如果是方法，会执行方法，不用加括号（authors=serializers.CharField(source='authors.all')）如在模型中定义一个方法，直接可以在在source指定执行
- views.py
from django.shortcuts import render from rest_framework.views import APIView from app01.models import Book from app01.MySerializer import BookSerializers from rest_framework.response import Response # Create your views here. class BooksView(APIView): def get(self,request): book_list = Book.objects.all() book_ser = BookSerializers(book_list,many=True) response = {"status":100,"message":"所有图书获取成功"} response['data'] = book_ser.data return Response(response) def post(self,request): book_ser = BookSerializers(data=request.data) if book_ser.is_valid(): book_ser.save() response = {"status":100,"message":"创建图书成功"} response['data'] = book_ser.data print(response) return Response(response) else: response = {"status": 100, "message": book_ser.errors} return Response(response)
- 结果
{ "status": 100, "message": "所有图书获取成功", "data": [ { "id": "1", "name": "红楼梦", "price": "88.00", "publish_date": "2019-02-25", "publish": "浙江出版社", "author": [ { "id": 1, "name": "曹雪芹", "age": 18, "info": "曹雪芹简介" }, { "id": 2, "name": "aaa", "age": 19, "info": "aaa简介" } ] }, { "id": "2", "name": "亚索", "price": "199.00", "publish_date": "2019-01-29", "publish": "浙江出版社", "author": [ { "id": 2, "name": "aaa", "age": 19, "info": "aaa简介" } ] } ] }
四、rest framework序列化之ModelSerializer
class BookSerializers(serializers.ModelSerializer): class Meta: model = models.Book # fields = "__all__" fields=['nid','title','authors','publish'] # exclude=('nid',) #不能跟fields同时用 # depth = 1 #深度控制，写 几 往里拿几层，层数越多，响应越慢，官方建议0--10之间，个人建议最多3层 publish=serializers.SerializerMethodField() def get_publish(self,obj): return obj.publish.name authors=serializers.SerializerMethodField() def get_authors(self,obj): ret=obj.authors.all() ss=AuthorSerializer(ret,many=True) return ss.data
五、序列化组件之请求数据校验和保存功能
class BookSerializers(serializers.ModelSerializer): class Meta: model=Book fields="__all__" #———————— class BookView(APIView): def post(self, request): # 添加一条数据 print(request.data) bs=BookSerializers(data=request.data) if bs.is_valid(): bs.save() # 生成记录 return Response(bs.data) else: return Response(bs.errors)
六、图书的增删改查resful接口
- view.py
class BooksView(APIView): def get(self, request, *args, **kwargs): response = {"status": 100, "message": "图书数据获取成功"} book_list = models.Book.objects.all() book_set = BookSerializers(book_list, many=True) response['data'] = book_set.data # return JsonResponse(response,safe=False,json_dumps_params={'ensure_ascii': False}) return Response(response) # def post(self,request): book_set = BookSerializers(data=request.data) print(book_set) if book_set.is_valid(): response = {"status": 100, "message": "图书添加成功"} book_set.save() response['data'] = book_set.data else: response = {"status": 404, "message": book_set.errors} response['data'] = "" return Response(response) class BookView(APIView): def get(self, request, pk, *args, **kwargs): book_obj = models.Book.objects.filter(pk=pk).first() book_set = BookSerializers(book_obj,many=False) if book_obj: response = {"status": 100, "message": "图书数据获取成功"} response['data'] = book_set.data else: response = {"status": 404, "message": "不存在该图书"} response['data'] = "" return Response(response) def delete(self,request,pk,*args,**kwargs): book_obj = models.Book.objects.filter(pk=pk) if book_obj: row = book_obj.delete() if row: response = {"status":200, "message": "数据删除成功"} else: response = {"status": 100, "message": "数据库数据删除失败"} else: response = {"status": 404, "message": "该图书不存在"} response['data'] = '' return Response(response) def put(self,request,pk,*args,**kwargs): book_obj = models.Book.objects.filter(pk=pk).first() print(book_obj) if book_obj: book_ser = BookSerializers(instance=book_obj,data=request.data) if book_ser.is_valid(): book_ser.save() response = {"status": 100, "message": "图书修改成功"} response['data'] = book_ser.data else: response = {"status": 404, "message": book_ser.errors} response['data'] = "" else: response = {"status": 404, "message":"不存在该图书，无法修改"} response['data'] = "" return Response(response)