books系列表接口

from django.contrib import admin
from django.urls import path,include

urlpatterns = [
    path(‘admin/‘, admin.site.urls),
    path(‘api/‘, include(‘api.urls‘)),
]

from django.urls import path, re_path
from api import views

urlpatterns = [
    path(‘books/‘, views.BookAPIView.as_view()),
    re_path(‘books/(?P<pk>\d+)‘, views.BookAPIView.as_view()),
]

from django.db import models


# Create your models here.
class BaseModel(models.Model):
    is_delete = models.BooleanField(default=False)
    # auto_now_add=True 只要记录创建，不需要手动插入时间，自动把当前时间插入
    create_time = models.DateTimeField(auto_now_add=True)
    # auto_now=True,只要更新，就会把当前时间插入
    last_update_time = models.DateTimeField(auto_now=True)

    # import datetime
    # create_time=models.DateTimeField(default=datetime.datetime.now)
    class Meta:
        # 单个字段，有索引，有唯一
        # 多个字段，有联合索引，联合唯一
        abstract = True  # 抽象表，不在数据库建立出表


class Book(BaseModel):
    # verbose_name admin中显示中文
    name = models.CharField(max_length=32, verbose_name=‘书名‘, help_text=‘这里填书名‘)
    price = models.DecimalField(max_digits=8, decimal_places=2)
    # 一对多的关系一旦确立，关联字段写在多的一方
    # to_field 默认不写，关联到Publish主键
    # db_constraint=False  逻辑上的关联，实质上没有外键练习，增删不会受外键影响，但是orm查询不影响
    publish = models.ForeignKey(to=‘Publish‘, on_delete=models.DO_NOTHING, db_constraint=False)
    # 多对多，跟作者，关联字段写在 查询次数多的一方

    # 什么时候用自动，什么时候用手动？第三张表只有关联字段，用自动    第三张表有扩展字段，需要手动写
    # 不能写on_delete
    authors = models.ManyToManyField(to=‘Author‘, db_constraint=False)

    class Meta:
        verbose_name_plural = ‘书表‘  # admin中表名的显示

    def __str__(self):
        return self.name

    @property
    def publish_name(self):
        return self.publish.name

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

class Publish(BaseModel):
    name = models.CharField(max_length=32)
    addr = models.CharField(max_length=32)

    def __str__(self):
        return self.name


class Author(BaseModel):
    name = models.CharField(max_length=32)
    sex = models.IntegerField(choices=((1, ‘男‘), (2, ‘女‘)))
    # 一对一关系，写在查询频率高的一方
    # OneToOneField本质就是ForeignKey+unique，自己手写也可以
    authordetail = models.OneToOneField(to=‘AuthorDetail‘, db_constraint=False, on_delete=models.CASCADE)


class AuthorDetail(BaseModel):
    mobile = models.CharField(max_length=11)

# 二、表断关联
# 1、表之间没有外键关联，但是有外键逻辑关联(有充当外键的字段)
# 2、断关联后不会影响数据库查询效率，但是会极大提高数据库增删改效率（不影响增删改查操作）
# 3、断关联一定要通过逻辑保证表之间数据的安全，不要出现脏数据，代码控制
# 4、断关联
# 5、级联关系
#       作者没了，详情也没：on_delete=models.CASCADE
#       出版社没了，书还是那个出版社出版：on_delete=models.DO_NOTHING
#       部门没了，员工没有部门(空不能)：null=True, on_delete=models.SET_NULL
#       部门没了，员工进入默认部门(默认值)：default=0, on_delete=models.SET_DEFAULT

from rest_framework import serializers
from api import models


# 写一个类，继ListSerializer,重写update
class BookListSerializer(serializers.ListSerializer):
    # def create(self, validated_data):
    #     print(validated_data)
    #     return super().create(validated_data)
    def update(self, instance, validated_data):
        print(instance)
        print(validated_data)
        # 保存数据
        # self.child:是BookModelSerializer对象
        # ll=[]
        # for i,si_data in enumerate(validated_data):
        #     ret=self.child.update(instance[i],si_data)
        #     ll.append(ret)
        # return ll
        return [
            # self.child.update(对象，字典) for attrs in validated_data
            self.child.update(instance[i], attrs) for i, attrs in enumerate(validated_data)
        ]


# 如果序列化的是数据库的表，尽量用ModelSerializer
class BookModelSerializer(serializers.ModelSerializer):
    # publish,显示出版社名称
    # 一种方案（只序列化可以，反序列化有问题）
    # publish=serializers.CharField(source=‘publish.name‘)
    # 第二种方案，models中写方法（看models.py）

    class Meta:
        list_serializer_class = BookListSerializer
        model = models.Book
        # fields=‘__all__‘
        # 用的少
        # depth=0
        fields = (‘id‘, ‘name‘, ‘price‘, ‘authors‘, ‘publish‘, ‘publish_name‘, ‘author_list‘)

        extra_kwargs = {
            ‘publish‘: {‘write_only‘: True},
            ‘publish_name‘: {‘read_only‘: True},
            ‘authors‘: {‘write_only‘: True},
            ‘author_list‘: {‘read_only‘: True}
        }

from django.shortcuts import render

# Create your views here.
from rest_framework.response import Response

from api import models
from  rest_framework.views import APIView
from rest_framework.generics import GenericAPIView
from api.ser import BookModelSerializer

class BookAPIView(APIView):
    def get(self,request,*args,**kwargs):
        #查询单个和查询所有，合到一起
        if not kwargs:
            # 查所有
            book_list=models.Book.objects.all().filter(is_delete=False)
            book_list_ser=BookModelSerializer(book_list,many=True)
            return Response(data=book_list_ser.data)
        #查一个
        book_list = models.Book.objects.filter(pk=kwargs.get(‘pk‘)).first()
        book_list_ser = BookModelSerializer(book_list)
        return Response(data=book_list_ser.data)

    def post(self, request, *args, **kwargs):
        # 具备增单条，和增多条的功能
        if isinstance(request.data, dict):

            book_ser = BookModelSerializer(data=request.data)
            book_ser.is_valid(raise_exception=True)
            book_ser.save()
            return Response(data=book_ser.data)
        elif isinstance(request.data, list):
            # 现在book_ser是ListSerializer对象
            from rest_framework.serializers import ListSerializer
            book_ser = BookModelSerializer(data=request.data, many=True)  # 增多条
            print(‘--------‘, type(book_ser))
            book_ser.is_valid(raise_exception=True)
            book_ser.save()
            # 新增---》ListSerializer--》create方法
            # def create(self, validated_data):
            #   self.child是BookModelSerializer对象
            #   print(type(self.child))
            #     return [
            #         self.child.create(attrs) for attrs in validated_data
            #     ]
            return Response(data=book_ser.data)

    def put(self, request, *args, **kwargs):
        # 改一个，改多个
        # 改一个
        if kwargs.get(‘pk‘, None):
            book = models.Book.objects.filter(pk=kwargs.get(‘pk‘)).first()
            book_ser = BookModelSerializer(instance=book, data=request.data, partial=True)  # 增多条
            # partial=True
            # partial 表示是否可以部分修改
            book_ser.is_valid(raise_exception=True)
            book_ser.save()
            return Response(data=book_ser.data)
        else:
            # 改多个,
            # 前端传递数据格式[{id:1,name:xx,price:xx},{id:1,name:xx,price:xx}]
            # 处理传入的数据  对象列表[book1，book2]  修改的数据列表[{name:xx,price:xx},{name:xx,price:xx}]
            book_list = []
            modify_data = []
            for item in request.data:
                # {id:1,name:xx,price:xx}

                pk = item.pop(‘id‘)
                book = models.Book.objects.get(pk=pk)
                book_list.append(book)
                modify_data.append(item)
            # 第一种方案，for循环一个一个修改
            # 把这个实现
            # for i,si_data in enumerate(modify_data):
            #     book_ser = BookModelSerializer(instance=book_list[i], data=si_data)
            #     book_ser.is_valid(raise_exception=True)
            #     book_ser.save()
            # return Response(data=‘成功‘)
            # 第二种方案，重写ListSerializer的update方法
            book_ser = BookModelSerializer(instance=book_list, data=modify_data, many=True)
            book_ser.is_valid(raise_exception=True)
            book_ser.save()  # ListSerializer的update方法,自己写的update方法
            return Response(book_ser.data)
            # request.data
            #
            # book_ser=BookModelSerializer(data=request.data)

    def delete(self, request, *args, **kwargs):
        # 单个删除和批量删除
        pk = kwargs.get(‘pk‘)
        pks = []
        if pk:
            # 单条删除
            pks.append(pk)
        # 不管单条删除还是多条删除，都用多条删除
        # 多条删除
        # {‘pks‘:[1,2,3]}
        else:
            pks = request.data.get(‘pks‘)
        # 把is_delete设置成true
        # ret返回受影响的行数
        ret = models.Book.objects.filter(pk__in=pks, is_delete=False).update(is_delete=True)
        if ret:
            return Response(data={‘msg‘: ‘删除成功‘})
        else:
            return Response(data={‘msg‘: ‘没有要删除的数据‘})