用各种思路实现五个接口的编写

用各种思路实现五个接口的编写

那么是哪五个接口呢？查询所有、查询单个、新增数据、修改数据、删除数据

各个方法其实用的都是同样的表数据所以干脆提前准备好 再说了代码也没那么复杂

# 1.创建Django项目随手修改配置文件
# 2.在models.py里面写表数据，代码如下
from django.db import models


class Book(models.Model):
    """书籍表"""
    name = models.CharField(max_length=32)
    price = models.CharField(max_length=32)
    publish = models.CharField(max_length=32)

# 3.进行数据库迁移
数据库就不用MySQL，因为结构简单就用sqlite而且是本地测试 因此不用改数据库配置
makemigrations
migrate
# 4.录入伪数据
双击数据库小图标就可以进去录入数据或用Navicat也可以的

一、基于Django原生写五个接口

1.视图层代码

from django.http import JsonResponse
from .models import Book
from django.views import View
import json


class BookView(View):
    """1.查所有数据"""
    def get(self, request):
        # 查询出所有图书,queryset对象，不能直接给前端
        books = Book.objects.all()
        book_list = []
        for book in books:
            book_list.append({'name': book.name, 'price': book.price, 'publish': book.publish})
        return JsonResponse(book_list, safe=False, json_dumps_params={'ensure_ascii': False})

   	"""2.新增一条数据"""
    def post(self, request):
        # 取出前端传入的数据
        name = request.POST.get('name')
        price = request.POST.get('price')
        publish = request.POST.get('publish')
        # 存到新增的对象字典
        book = Book.objects.create(name=name, price=price, publish=publish)
        # 返回新增的对象字典
        return JsonResponse({'name': book.name, 'price': book.price, 'publish': book.publish})


class BookDetailView(View):
    """3.查询单个数据"""
    def get(self, request, pk):
        book = Book.objects.filter(pk=pk).first()
        return JsonResponse({'id': book.id, 'name': book.name, 'price': book.price, 'publish': book.publish})

    """4.修改数据"""
    def put(self, request, pk):
        # 查到要改的
        book = Book.objects.filter(pk=pk).first()
        # 前端使用json格式提交 自己保存
        book_dict = json.loads(request.body)
        book.name = book_dict.get('name')
        book.price = book_dict.get('price')
        book.publish = book_dict.get('publish')
        book.save()
        return JsonResponse({'id': book.id, 'name': book.name, 'price': book.price, 'publish': book.publish})

    def delete(self, request, pk):
        """5.删除数据"""
        Book.objects.filter(pk=pk).delete()
        return JsonResponse(data={})

2.路由层代码

from django.contrib import admin
from django.urls import path
from app01 import views


urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/v1/books/<int:pk>/',views.BookDetailView.as_view()),
    path('api/v1/books/', views.BookView.as_view()),
]

二、基于drf实现五个接口的编写

1.视图层代码

from .serializer import BookSerializer
from rest_framework.viewsets import ModelViewSet
class BookView(ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializer

2.序列化代码

from rest_framework import serializers
from .models import Book
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = Book
        fields = '__all__'

3.路由层代码

from rest_framework.routers import SimpleRouter
router = SimpleRouter()
router.register('books', views.BookView, 'books')

urlpatterns = [
    path('admin/', admin.site.urls),
]
# 两个列表相加  [1,2,4] +  [6,7,8]=
urlpatterns += router.urls

三、基于序列化器编写五个接口

1.路由层代码

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.BookDetailView.as_view()),

]

2.视图层代码

from django.shortcuts import render
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import Book
from .serializer import BookSerializer


class BookView(APIView):
    """1.查所有数据 序列化过程"""
    def get(self, request):
        books = Book.objects.all()
        # 需要序列化类来完成---得有序列化类即BookSerializer
        # instance参数是要序列化的数据books queryset对象
        # 要传的数据是多条那就得加上many=True参数，如果是单挑就不用传
        ser = BookSerializer(instance=books, many=True)

        return Response(ser.data)

    def post(self, request):
        """2.新增数据 反序列化过程"""
        # request.data 前端提交数据---校验数据---存数据，前端传入的数据给data参数
        ser = BookSerializer(data=request.data)
        # 校验数据
        if ser.is_valid():
            ser.save()
            return Response({'code':100, 'msg':'新增成功', 'result':ser.data})
        else:
            return Response({'code':101, 'msg':ser.errors})



class BookDetailView(APIView):
    """3.获取单个数据 序列化过程"""
    def get(self, request, *args, **kwargs):
        book = Book.objects.filter(pk=kwargs.get('pk')).first()
        ser = BookSerializer(instance=book)
        return Response(ser.data)

    def put(self, requet, pk):
         """4.修改数据 反序列化过程"""
        book = Book.objects.filter(pk=pk).first()
        ser = BookSerializer(data=requet.data, instance=book)
        if ser.is_valid():
            ser.save()
            return Response({'code':100, 'msg':'修改数据', 'result':ser.data})
        else:
            return Response({'code':101, 'msg':ser.errors})


    def delete(self, request, pk):
        Book.objects.filter(pk=pk).delete()
        return Response({'code':100,'msg':'删除成功'})

3.序列化代码

from rest_framework import serializers
from rest_framework.exceptions import ValidationError
from .models import Book


class BookSerializer(serializers.Serializer):
    # 序列化模型表的三个字段
    name = serializers.CharField()
    price = serializers.CharField()
    publish = serializers.CharField()

    def create(self, validated_data):
        """数据保存逻辑"""
        # 保存到数据库
        # validated_data是校验过后的数据
        book = Book.objects.create(**validated_data)
        return book

    def update(self, instance, validated_data):
        """数据更新逻辑"""
        # instance是要修改的对象
        instance.name = validated_data.get('name')
        instance.price = validated_data.get('price')
        instance.publish = validated_data.get('publish')
        # orm的单个对象 修改了单个对象的属性 只要调用对象.save就能把修改保存的数据库
        instance.save()
        # 返回修改后的对象
        return instance

    def validate_name(self, name):
        # 校验name是否合法
        if name.startswith('sb'):
            # 校验啊不能通过 抛异常
            raise ValidationError('名字不能以sb开头')
        else:
            return name

    def validate(self, attrs):
        # 校验过后的数据 书名跟出版社名字不能一样
        if attrs.get('name') == attrs.get('publish'):
            raise ValidationError('书名和出版社名不能一样')
        else:
            return attrs