序列化多表操作、請求與響應、視圖組件(子類與拓展類)、繼承GenericAPIView類重寫介面
今日內容概要
內容詳細
1、序列化多表操作
模型類 models.py中
# 新建django項目
# 創建表 模型類models.py中:
from django.db import models
# 4張表
class Book(models.Model):
name = models.CharField(max_length=32)
price = models.DecimalField(max_digits=5, decimal_places=2)
publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE) # to='Publish' 自動關聯publish表主鍵 // on_delete=models.CASCADE 級聯刪除
authors = models.ManyToManyField(to='Author')
def __str__(self):
return self.name
@property
def publish_detail(self): # 訂製欄位
return {'name': self.publish.name, 'addr': self.publish.city}
@property
def author_list(self): # 訂製欄位
l = []
# print(self.authors.all())
for author in self.authors.all():
# print(author.author_detail)
l.append({'name': author.name, 'age': author.age, 'addr': author.author_detail.addr})
return l
class Author(models.Model):
name = models.CharField(max_length=32)
age = models.IntegerField()
author_detail = models.OneToOneField(to='AuthorDatail', on_delete=models.CASCADE)
# OneToOneField 就是 ForeignKey + unique=True
class AuthorDatail(models.Model):
telephone = models.BigIntegerField()
addr = models.CharField(max_length=64)
class Publish(models.Model):
name = models.CharField(max_length=32)
city = models.CharField(max_length=32)
email = models.EmailField()
"""
在每個表中寫入數據一一對應
第五個自動創建的關聯表 也寫入數據
"""

創建序列化類 serializer.py
from .models import *
from rest_framework import serializers
class BookSerializer(serializers.ModelSerializer):
class Meta:
model = Book
# fields = '__all__'
fields = ['id', 'name', 'price', 'authors', 'publish', 'publish_detail', 'author_list']
# 由於前端的publish與authors會顯示為:id 所以需要訂製序列化欄位
# depth=1 # 等同於訂製序列化的欄位(2種方案) 但是盡量不要用,因為它是關聯表一層全部取出來
# 訂製序列化的欄位(2種方案)選擇表模型中: 顯示出版社名、地址;作者名年齡地址
extra_kwargs = {
'publish': {'write_only': True}, # 原有的欄位就不需要再顯示
'authors': {'write_only': True},
}
class AuthorSerializer(serializers.ModelSerializer):
class Meta:
model = Author
fields = '__all__'
class AuthorDetailSerialzier(serializers.ModelSerializer):
class Meta:
model = AuthorDatail
fields = '__all__'
class PublishSerialzier(serializers.ModelSerializer):
class Meta:
model = Publish
fields = '__all__'
視圖類 views.py中:
from .serializer import *
from rest_framework.response import Response
from rest_framework.views import APIView
from app01.models import Book
class BookView(APIView):
# 查詢所有圖書
def get(self, request):
book_list = Book.objects.all()
ser = BookSerializer(instance=book_list, many=True)
return Response(ser.data)
# 新增圖書數據
def post(self, request):
ser = BookSerializer(data=request.data)
if ser.is_valid():
ser.save()
return Response({"code": 100, 'msg': '新增成功', 'data': ser.data})
return Response({"code": 101, 'msg': '新增失敗', 'err': ser.errors})
class BookDetailView(APIView):
# 查詢單條數據
def get(self, request, pk):
book = Book.objects.all().filter(pk=pk).first()
ser = BookSerializer(instance=book)
return Response(ser.data)
# 修改數據
def put(self, request, pk):
book = Book.objects.all().filter(pk=pk).first()
ser = BookSerializer(instance=book, data=request.data)
if ser.is_valid():
ser.save()
return Response({"code": 100, 'msg': '修改成功', 'data': ser.data})
return Response({"code": 101, 'msg': '修改出錯', 'err': ser.errors})
# 刪除數據
def delete(self, request, pk):
Book.objects.filter(pk=pk).delete()
return Response({"code": 100, 'msg': '刪除成功'})
路由 urls.py中:
from django.contrib import admin
from django.urls import path
from app01 import views
urlpatterns = [
path('admin/', admin.site.urls),
path('books/', views.BookView.as_view()),
path('books/<int:pk>', views.BookView.as_view()),
]

2、請求與相應
2.1 請求
# 請求就是指:Request 類的對象
>>> 新的request對象
# 導入:
from rest_framework.request import Request
# 需要記住的源碼:
__getattr__
request.data
request.query_parmas--->self._request.GET
restful規範里,請求地址中帶過濾(查詢)條件
get請求地址中提交的數據在GET中,
query_parmas:查詢參數
# 了解
默認情況下,可以解析 urlencoded,formdata,json
# 案例:
如果我們寫了一個介面,想只能處理json格式,或者只能處理formdata
1.局部配置 在views.py中:
from rest_framework.parsers import JSONParser, FormParser, MultiPartParser
class PublishView(APIView):
# 局部使用,只針對當前視圖類有效
# 只想處理json格式
# parser_classes = [JSONParser,FormParser,MultiPartParser] # 默認下 是處理三種格式數據
parser_classes = [JSONParser] # 只允許處理 JSONParser格式
def post(self, request):
print(request.data)
return Response('post---publish')
2.全局配置-->要在配置文件中添加:
# REST_FRAMEWORK 以後是drf的配置
# 所有介面都只能解析json格式
REST_FRAMEWORK = {
'DEFAULT_PARSER_CLASSES': [
'rest_framework.parsers.JSONParser',
],
}
3.全局配置解析json,局部某個視圖函數想能解析formdata格式
視圖類中配置一下即可 就是局部配置(按照使用順序)
# 如果局部配置如下,會怎麼樣
parser_classes = [] # 所有格式都補不能解析了
# 使用順序:
即使我們沒有配置局部或者全局,也有默認配置:3個數據模式都能解析
視圖類中配的(優先用)
項目配置文件的配置(其次)
drf有默認配置(最後)
drf的默認配置:from rest_framework import settings
# 總結:
一般情況下,都使用默認即可,不用配置(三種格式數據都能解析)

2.2 響應
# 其實就是:Respone 返回給前端的
# 導入:
from rest_framework.response import Response
# 源碼分析
1.屬性:
data=None, # 返回給前端的數據:可以是 字元串,字典,列表 就是給http響應body體中內容-->也可以是response對象中取出數據並 處理
status=None, # 響應狀態碼:1xx,2xx,3xx,默認是200
headers=None, # 響應頭 字典
了解:
template_name=None, # 模板名字(不用),用瀏覽器訪問時,可以改
exception=False, # 異常處理
content_type=None # 響應編碼格式
from rest_framework.status import HTTP_201_CREATED
Response(ser.data,status=HTTP_201_CREATED)
2.響應格式 跟解析數據格式類似
# 局部配置 在視圖類 views.py中配置:
from rest_framework.renderers import JSONRenderer, BrowsableAPIRenderer
class BookDetailView(APIView):
renderer_classes = [JSONRenderer, ]
# 全局設置 在配置文件中配置:
REST_FRAMEWORK = {
'DEFAULT_RENDERER_CLASSES': ( # 默認響應渲染類
'rest_framework.renderers.JSONRenderer', # json渲染器
'rest_framework.renderers.BrowsableAPIRenderer', # 瀏覽API渲染器
)
}

3、視圖組件
# APIView
from rest_framework.views import APIView
類屬性 renderer_classes,parser_classes...
get方法,post方法,delete方法 寫法跟之前的View一樣,只不過request對象變成了新的request
比之前的View多了三大認證和全局異常處理
# GenericAPIView 繼承了APIView 但是多了屬性和方法
from rest_framework.generics import GenericAPIView
屬性(先記兩個):
queryset = None
serializer_class = None
方法:
get_queryset
get_object
get_serializer
# 5個視圖擴展類(不是視圖類,沒有集成APIView,需要配合GenericAPIView)
from rest_framework.mixins import
CreateModelMixin,
ListModelMixin,
DestroyModelMixin,
RetrieveModelMixin,
UpdateModelMixin
# 9個視圖子類
from rest_framework.generics import
CreateAPIView,
ListAPIView,
DestroyAPIView,
RetrieveAPIView,
UpdateAPIView,
ListCreateAPIView,
RetrieveUpdateAPIView,
RetrieveUpdateDestroyAPIView,
RetrieveDestroyAPIView
# 視圖集
from rest_framework.viewsets import
# 兩個視圖類
ModelViewSet, ReadOnlyModelViewSet,
# 視圖類
ViewSet, GenericViewSet,
# 魔法類
ViewSetMixin
繼承GenericAPIView 重寫視圖類
# 添加路由:
path('publishs/<int:pk>', views.PublishDetailView.as_view()),
# 視圖類複製過來並做修改:
# 第一層:繼承APIView寫視圖類
# 第二層:繼承GenericAPIView寫視圖類
from rest_framework.generics import GenericAPIView
class PublishView(GenericAPIView):
queryset = Publish.objects.all()
serializer_class = PublishSerialzier
# 查詢所有圖書
def get(self, request):
# obj = self.queryset
obj = self.get_queryset() # 等同於上面,obj = self.queryset 並且更好一些
# ser = self.serializers(instance=obj, many=True)
# ser=self.get_serializer_class()(instance=obj,many=True) # 等同於上面
ser = self.get_serializer(instance=obj, many=True) # 等同於上面
return Response(ser.data)
# 新增圖書數據
def post(self, request):
# ser = BookSerializer(data=request.data)
ser = self.get_serializer(data=request.data) # 等同於上面
if ser.is_valid():
ser.save()
return Response({"code": 100, 'msg': '新增成功', 'data': ser.data})
return Response({"code": 101, 'msg': '新增失敗', 'err': ser.errors})
class PublishDetailView(GenericAPIView):
queryset = Publish.objects.all()
serializer_class = PublishSerialzier
# 查詢單條數據
def get(self, request, *args, **kwargs):
# book = Book.objects.all().filter(pk=pk).first()
obj = self.get_object() # 等同於上面
# ser = BookSerializer(instance=book)
ser = self.get_serializer(instance=obj) # 等同於上面
return Response(ser.data)
# 修改數據
def put(self, request, *args, **kwargs):
# book = Book.objects.all().filter(pk=pk).first()
obj = self.get_object() # 等同於上面
# ser = BookSerializer(instance=book, data=request.data)
ser = self.get_serializer(instance=obj, data=request.data) # 等同於上面
if ser.is_valid():
ser.save()
return Response({"code": 100, 'msg': '修改成功', 'data': ser.data})
return Response({"code": 101, 'msg': '修改出錯', 'err': ser.errors})
# 刪除數據
def delete(self, request, *args, **kwargs):
# Book.objects.filter(pk=pk).delete()
self.get_object().delete()
return Response({"code": 100, 'msg': '刪除成功'})

4、通過GenericAPIView + 5個視圖擴展類 重寫視圖類
# 第三層:GenericAPIView+5個視圖擴展類 重寫視圖類
from rest_framework.generics import GenericAPIView
from rest_framework.mixins import CreateModelMixin, ListModelMixin, DestroyModelMixin, RetrieveModelMixin, UpdateModelMixin
class PublishView(GenericAPIView, CreateModelMixin, ListModelMixin):
queryset = Publish.objects.all()
serializer_class = PublishSerialzier
# 查詢所有圖書
def get(self, request):
return super().list(request) # list(request)ListModelMixin的方法
# 新增圖書數據
def post(self, request):
return super().list(request) # create(request)ListModelMixin的方法
class PublishDetailView(GenericAPIView, UpdateModelMixin, RetrieveModelMixin, DestroyModelMixin):
queryset = Publish.objects.all()
serializer_class = PublishSerialzier
# 查詢單條數據
def get(self, request, *args, **kwargs):
return super().retrieve(request, *args, **kwargs)
# 修改數據
def put(self, request, *args, **kwargs):
return super().update(request, *args, **kwargs)
# 刪除數據
def delete(self, request, *args, **kwargs):
return super().destroy(request, *args, **kwargs)
