drf—— Book系列連表接口

注意：

# 注意：之後全部的數據刪除，儘可能用軟刪除，使用一個字段標誌是否刪除，而不是真正的從數據庫中刪除
    -好處：1 這樣刪除數據不會影響索引，不會致使索引失效
          2 以前存的用戶數據還在，以備之後使用

models.py--->數據遷移

# 抽象出一個基表（再也不數據庫生成,abstract=True）,只用來繼承

class BaseModel(models.Model):
    is_delete = models.BooleanField(default=False)
    create_time = models.DateTimeField(auto_now_add=True)

    class Meta:
        # 基表必須設置abstract，基表就是給普通Model類繼承使用的，設置了abstract就不會完成數據庫遷移完成建表
        abstract = True


class Book(BaseModel):
    name = models.CharField(max_length=16)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    publish = models.ForeignKey(to='Publish', db_constraint=False, on_delete=models.DO_NOTHING)
    # 重點：多對多外鍵實際在關係表中，ORM默認關係表中兩個外鍵都是級聯
    # ManyToManyField字段不提供設置on_delete，若是想設置關係表級聯，只能手動定義關係表
    authors = models.ManyToManyField(to='Author', related_name='books', db_constraint=False)

    @property
    def publish_name(self):
        return self.publish.name
    @property
    def author_list(self):
        # ll=[]
        # for author in self.authors.all():
        #     ll.append({'name':author.name,'sex':author.get_sex_display()})
        return [{'name': author.name, 'sex': author.get_sex_display()} for author in self.authors.all()]


class Publish(BaseModel):
    name = models.CharField(max_length=16)
    address = models.CharField(max_length=64)


class Author(BaseModel):
    name = models.CharField(max_length=16)
    sex = models.IntegerField(choices=[(0, '男'), (1, '女')], default=0)


class AuthorDetail(BaseModel):
    mobile = models.CharField(max_length=11)
    # 有做者能夠沒有詳情，刪除做者，詳情必定會被級聯刪除
    # 外鍵字段爲正向查詢字段，related_name是反向查詢字段
    author = models.OneToOneField(to='Author', related_name='detail', db_constraint=False, on_delete=models.CASCADE)

admin.py

from django.contrib import admin
from app01 import models

admin.site.register(models.Book)
admin.site.register(models.Publish)
admin.site.register(models.Author)
admin.site.register(models.AuthorDetail)

建立一個超級用戶，登陸admin後臺管理，造出一些數據（books ,authors,publish）

serializer.py

# 圖書表序列化類

from app01 import models
from rest_framework import serializers

class ListBookSerializer(serializers.ListSerializer):
    # def create(self, validated_data):
    #     print('=======',validated_data)
    #     return '1'
    def update(self, instance, validated_data):
        print(instance) # book_list:是一堆圖書對象
        print(validated_data) # 列表套字典，是要修改的數據

        return [self.child.update(book, validated_data[i]) for i, book in enumerate(instance)]


class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        list_serializer_class=ListBookSerializer # 指定many=True的時候，生成的ListBookSerializer的對象了
        fields = ['name', 'price', 'publish', 'authors', 'publish_name', 'author_list']
        extra_kwargs = {
            'publish': {'write_only': True},
            'authors': {'write_only': True},
            'publish_name': {'read_only': True},
            'author_list': {'read_only': True},

        }

    # def create(self, validated_data):
    #     print(validated_data)

utils.py

from rest_framework.response import Response

class APIResponse(Response):
    def __init__(self, code=100, msg='成功', data=None, status=None,
                 headers=None, content_type=None, **kwargs):
        dic = {'code': code, 'msg': msg}
        if data:
            dic['data'] = data
        dic.update(kwargs)
        super().__init__(data=dic, status=status, headers=headers, content_type=content_type)


from rest_framework.views import exception_handler


def common_exception(exc, context):
    # 先調用REST framework默認的異常處理方法得到標準錯誤響應對象
    response = exception_handler(exc, context)
    # 在此處補充自定義的異常處理
    if response is None:
        response = Response(data={'code':999,'msg':str(exc)})

    return response

settings.py

INSTALLED_APPS = [
    ...
    'rest_framework'
]

REST_FRAMEWORK = {
    # 配置全局異常
    'EXCEPTION_HANDLER': 'app01.utils.common_exception'
}

 

views.py

# book表單增羣增
from app01 import serializer
from app01 import models
from rest_framework.views import APIView
from app01.utils import APIResponse


class BookView(APIView):
    def post(self, request, *args, **kwargs):
        if isinstance(request.data, dict):
            # 增一條
            ser = serializer.BookSerializer(data=request.data)
            ser.is_valid(raise_exception=True)
            ser.save()
            return APIResponse(data=ser.data)
        elif isinstance(request.data, list):
            # 增多條(讓many=True就能夠了）
            ser = serializer.BookSerializer(data=request.data, many=True)
            # 內部如何實現的？
            # many=True,ser不是BookSerializer對象，而是ListSerializer對象，套了一個個的BookSerializer
            print(type(ser))
            ser.is_valid(raise_exception=True)
            #
            from rest_framework.serializers import ListSerializer
            ser.save()  # ListSerializer的save
            return APIResponse(msg='增長%s條成功' % len(request.data))
    def get(self, request, *args, **kwargs):
        pk = kwargs.get('pk', None)
        if pk:
            # 單查
            # 方式一
            # book=models.Book.objects.filter(id=pk).filter(is_delete=False).first()
            # if not book:
            #     raise Exception('要查詢的不存在')

            # 方式二
            book = models.Book.objects.get(id=pk, is_delete=False)
            ser = serializer.BookSerializer(instance=book)

        else:
            # 查全部
            book_list = models.Book.objects.all().filter(is_delete=False)
            ser = serializer.BookSerializer(instance=book_list, many=True)
        return APIResponse(data=ser.data)

    def delete(self, request, *args, **kwargs):
        pk = kwargs.get('pk', None)
        pks = []
        if pk:
            # 單條刪除
            # res=models.Book.objects.filter(id=pk).update(is_delete=True)
            # print(res)
            # return APIResponse(msg='刪除成功')
            pks.append(pk)
        else:
            pks = request.data

        res = models.Book.objects.filter(id__in=pks).update(is_delete=True)
        if res >= 1:
            return APIResponse(msg='刪除%s條成功' % res)
        else:
            # raise Exception('沒有要刪除的數據')
            return APIResponse(code=999, msg='沒有要刪除的數據')

    def put(self, request, *args, **kwargs):
        pk = kwargs.get('pk', None)
        if pk:
            # 單條修改
            book = models.Book.objects.get(id=pk, is_delete=False)
            ser = serializer.BookSerializer(instance=book, data=request.data)
            ser.is_valid(raise_exception=True)
            ser.save()
            return APIResponse(msg='修改爲功')
        else:
            # 分析：ListSerializer的update方法沒有寫，須要咱們本身寫
            from rest_framework.serializers import ListSerializer
            # pks=[item['id'] for item in request.data]

            # 若是不重寫ListSerializer的update方法，這是存不進去的
            pks = []
            for item in request.data:
                pks.append(item['id'])
                item.pop('id')

            print(request.data)
            book_list = models.Book.objects.filter(id__in=pks, is_delete=False)
            ser = serializer.BookSerializer(instance=book_list, data=request.data, many=True)
            print(type(ser))
            ser.is_valid(raise_exception=True)
            ser.save()
            return APIResponse(msg='修改%s條成功')

urls.py

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

urlpatterns = [
    ### book表
    path('books/', views.BookView.as_view()),
    re_path('books/(?P<pk>\d+)', views.BookView.as_view()),

]