目录python
Model类的内部配置Meta类要设置abstract=True,这样的Model类就是用来做为基表git
多表:Book,Publish,Author,AuthorDetail数据库
db_constraint=Falsedjango
一、一对多:外键放在多的一方
二、多对多:外键放在经常使用的一方
三、一对一:外键放在不经常使用的一方
四、外键字段为正向查询字段,related_name是反向查询字段json
author = models.OneToOneField(to='Author', related_name='detail', db_constraint=False, on_delete=models.CASCADE)
有做者能够没有详情,删除做者,详情必定会被级联删除api
外键字段为正向查询字段,related_name是反向查询字段安全
related_name='books',反向查询能够直接点books,反向查询的字段
db_constraint=False,去掉外键创建的关联
on_delete=models.DO_NOTHING,不执行级联删除app
# ManyToManyField字段不提供设置on_delete,若是想设置关系表级联,只能手动定义关系表 authors = models.ManyToManyField(to='Author', related_name='books', db_constraint=False)
from django.db import models from django.conf import settings # 1、基表 # Model类的内部配置Meta类要设置abstract=True,这样的Model类就是用来做为基表 # 多表:Book,Publish,Author,AuthorDetail class BaseModel(models.Model): is_delete = models.BooleanField(default=False) create_time = models.DateTimeField(auto_now_add=True) class Meta: # 基表必须设置abstract,基表就是给普通Model类继承使用的, # 设置了abstract就不会完成数据库迁移完成建表 # abstract 目的就是只为了继承设置,而且告诉django,不要进行创建这个表格 abstract = True # 抽象的表 class Book(BaseModel):# 继承表 name = models.CharField(max_length=16) price = models.DecimalField(max_digits=5, decimal_places=2) # related_name='books',反向查询能够直接点books,反向查询的字段 # db_constraint=False,去掉外键创建的关联 # on_delete=models.DO_NOTHING,不执行级联删除 publish = models.ForeignKey(to='Publish', related_name='books', db_constraint=False, on_delete=models.DO_NOTHING) # 重点:多对多外键实际在关系表中,ORM默认关系表中两个外键都是级联 # db_constraint=False # ManyToManyField字段不提供设置on_delete,若是想设置关系表级联,只能手动定义关系表 authors = models.ManyToManyField(to='Author', related_name='books', db_constraint=False) # 自定义连表深度,不须要反序列化,由于自定义插拔属性不参与反序列化 @property def publish_name(self): return self.publish.name @property def author_list(self): temp_author_list = [] for author in self.authors.all(): temp_author_list.append({ 'name': author.name, 'sex': author.get_sex_display(), 'mobile': author.detail.mobile }) return temp_author_list 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) # 有做者能够没有详情,删除做者,详情必定会被级联删除 # 外键字段为正向查询字段,related_name是反向查询字段 author = models.OneToOneField(to='Author', related_name='detail', db_constraint=False, on_delete=models.CASCADE)
返回信息组件化
格式:post
{ 'status':0, 'msg':"", 'results':'', ... }
from rest_framework.response import Response class APIResponse(Response): # 格式化data def __init__(self, status=0, msg='ok', results=None, http_status=None, headers=None, exception=False, **kwargs): data = { # json的response基础有数据状态码和数据状态信息 'status': status, 'msg': msg } if results is not None: # 后台有数据,响应数据 data['results'] = results data.update(**kwargs) # 后台的一切自定义响应数据直接放到响应数据data中 super().__init__(data=data, status=http_status, headers=headers, exception=exception)
from rest_framework.views import exception_handler as drf_exception_handler from rest_framework.response import Response def exception_handler(exc, context): # drf_exception_handler的执行结果就是异常信息的Response对象或None # 是Response对象能够直接返回 # 是None能够从exc中拿到异常信息,从context拿到是谁出现的异常,本身格式化成Response对象返回 # 重点:自定义异常模块目的是记录异常信息到日志文件 - 产品阶段 response = drf_exception_handler(exc, context) if response is None: response = Response({'detail': '%s' % exc}, status=500, exception=True) # logging.error(response.data) return response
REST_FRAMEWORK = { # 异常 # 'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler',#系统异常 'EXCEPTION_HANDLER': 'api.utils.exception_handler',#重写异常 }
# 了解 fields = '__all__'#返回全部 exclude = ('id', )#除了id 其余的返回 depth = 1#连表深度查询返回 #下面俩个不能一块儿使用 fields = '__all__'#返回全部 exclude = ('id', )#除了id 其余的返回
from rest_framework import serializers from . import models class BookListSerializer(serializers.ListSerializer): # 一、create方法父级ListSerializer已经提供了 # def create(self, validated_data): # # 经过self.child来访问绑定的ModelSerializer # print(self.child) # raise Exception('我不提供') # 二、父级ListSerializer没有经过update方法的实现体,须要本身重写 def update(self, instance, validated_data): # print(instance) # print(validated_data) return [ self.child.update(instance[i], attrs) for i, attrs in enumerate(validated_data) ] class BookModelSerializer(serializers.ModelSerializer): # 经过BookModelSerializer.Meta.list_serializer_class来访问绑定的ListSerializer class Meta: # 关联ListSerializer完成群增群改 ################################################################# list_serializer_class = BookListSerializer model = models.Book # fields = ('name', 'price', 'publish', 'authors') # fields = ('name', 'price', 'publish_name', 'author_list') # 了解 # fields = '__all__' # exclude = ('id', ) # depth = 1 # 序列化与反序列化整合 fields = ('name', 'price', 'publish_name', 'author_list', 'publish', 'authors') extra_kwargs = { 'publish': { 'write_only': True }, 'authors': { 'write_only': True } }
子序列化都是提供给外键(正向方向)完成深度查询的,外键数据是惟一:many=False;不惟一:many=True
只能参与序列化,且反序列化不能写(反序列化外键字段会抛异常)
# 前提:若是只有查需求的接口,自定义深度还能够用子序列化方式完成 class PublishModelSerializer(serializers.ModelSerializer): # 子序列化都是提供给外键(正向方向)完成深度查询的,外键数据是惟一:many=False;不惟一:many=True # 注:只能参与序列化,且反序列化不能写(反序列化外键字段会抛异常) books = BookModelSerializer(many=True) class Meta: model = models.Publish fields = ('name', 'address', 'books')
from django.conf.urls import url from . import views urlpatterns = [ url(r'^books/$', views.BookAPIView.as_view()), url(r'^books/(?P<pk>\d+)/$', views.BookAPIView.as_view()), ]
from rest_framework.views import APIView from rest_framework.response import Response from . import models, serializers from .response import APIResponse class BookAPIView(APIView):
# 单查、群查 def get(self, request, *args, **kwargs): pk = kwargs.get('pk') if pk: book_obj = models.Book.objects.filter(pk=pk, is_delete=False).first() if not book_obj: return APIResponse(1, 'pk error', http_status=400) book_data = serializers.BookModelSerializer(book_obj).data return APIResponse(results=book_data) book_query = models.Book.objects.filter(is_delete=False).all() return APIResponse(0, 'ok', data=serializers.BookModelSerializer(book_query, many=True).data)
# 单删、群删 def delete(self, request, *args, **kwargs): """ 单删:前台数据为pk,接口为 /books/(pk)/ 群删:前台数据为pks,接口为 /books/ """ pk = kwargs.get('pk') # 将单删群删逻辑整合 if pk: # /books/(pk)/的接口就不考虑群删,就固定为单删 pks = [pk] else: pks = request.data.get('pks') # 前台数据有误(主要是群删没有提供pks) if not pks: return APIResponse(1, 'delete error', http_status=400) # 只要有操做受影响行,就是删除成功,反之失败 rows = models.Book.objects.filter(is_delete=False, pk__in=pks).update(is_delete=True) if rows: return APIResponse(0, 'delete ok') return APIResponse(1, 'delete failed')
# 单增、群增 def post(self, request, *args, **kwargs): """ 单增:前台提交字典,接口 /books/ 群增:前台提交列表套字典,接口 /books/ """ request_data = request.data if isinstance(request_data, dict): # 单增 book_ser = serializers.BookModelSerializer(data=request_data) if book_ser.is_valid(): book_obj = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj).data) return APIResponse(1, msg=book_ser.errors) elif isinstance(request_data, list) and len(request_data) != 0 : # 群增 book_ser = serializers.BookModelSerializer(data=request_data, many=True) book_ser.is_valid(raise_exception=True) book_obj_list = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj_list, many=True).data) else: return APIResponse(1, 'data error', http_status=400)
父级ListSerializer没有经过update方法的实现体,须要本身重写
class BookListSerializer(serializers.ListSerializer): # 一、create方法父级ListSerializer已经提供了 # def create(self, validated_data): # # 经过self.child来访问绑定的ModelSerializer # print(self.child) # raise Exception('我不提供') # 二、父级ListSerializer没有经过update方法的实现体,须要本身重写 def update(self, instance, validated_data): # print(instance) # print(validated_data) return [ self.child.update(instance[i], attrs) for i, attrs in enumerate(validated_data) ]
class BookModelSerializer(serializers.ModelSerializer): # 经过BookModelSerializer.Meta.list_serializer_class来访问绑定的ListSerializer class Meta: # 关联ListSerializer完成群增群改 list_serializer_class = BookListSerializer
instance=obj
# 修改和新增,都须要经过数据,数据依旧给data,修改与新增不一样点,instance要被赋值为被修改对象 book_ser = serializers.BookModelSerializer(instance=book_obj, data=request_data)
# 单总体改、群总体改 def put(self, request, *args, **kwargs): """ 单总体改:前台提交字典,接口 /books/(pk)/ 群总体改:前台提交列表套字典,接口 /books/,注每个字典均可以经过pk """ pk = kwargs.get('pk') request_data = request.data if pk: # 单改 try: book_obj = models.Book.objects.get(pk=pk) except: return APIResponse(1, 'pk error') # 修改和新增,都须要经过数据,数据依旧给data,修改与新增不一样点,instance要被赋值为被修改对象 book_ser = serializers.BookModelSerializer(instance=book_obj, data=request_data) book_ser.is_valid(raise_exception=True) book_obj = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj).data) else: # 群改 if not isinstance(request_data, list) or len(request_data) == 0: return APIResponse(1, 'data error', http_status=400) # [{pk:1,...}, {pk:3,...}, {pk:100,...}] => [obj1, obj3, obj100] + [{...}, {...}, {...}] # 要考虑pk对应的对象是否被删,以及pk没有对应的对象 # 假设pk3被删,pk100没有 => [obj1] + [{...}] # 注:必定不要在循环体中对循环对象进行增删(影响对象长度)的操做 obj_list = [] data_list = [] for dic in request_data: # request_data多是list,单内部不必定是dict try: pk = dic.pop('pk') try: obj = models.Book.objects.get(pk=pk, is_delete=False) obj_list.append(obj) data_list.append(dic) except: pass except: return APIResponse(1, 'data error', http_status=400) book_ser = serializers.BookModelSerializer(instance=obj_list, data=data_list, many=True) book_ser.is_valid(raise_exception=True) book_obj_list = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj_list, many=True).data)
partial=True
# 局部修改就是在总体修改基础上设置partial=True,将全部参与反序列化字段设置为required=False book_ser = serializers.BookModelSerializer(instance=book_obj, data=request_data, partial=True)
# 单局部改、群局部改 def patch(self, request, *args, **kwargs): """ 单总体改:前台提交字典,接口 /books/(pk)/ 群总体改:前台提交列表套字典,接口 /books/,注每个字典均可以经过pk """ pk = kwargs.get('pk') request_data = request.data if pk: try: book_obj = models.Book.objects.get(pk=pk) except: return APIResponse(1, 'pk error') # 局部修改就是在总体修改基础上设置partial=True,将全部参与反序列化字段设置为required=False book_ser = serializers.BookModelSerializer(instance=book_obj, data=request_data, partial=True) book_ser.is_valid(raise_exception=True) book_obj = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj).data) else: # 群改 if not isinstance(request_data, list) or len(request_data) == 0: return APIResponse(1, 'data error', http_status=400) # [{pk:1,...}, {pk:3,...}, {pk:100,...}] => [obj1, obj3, obj100] + [{...}, {...}, {...}] # 要考虑pk对应的对象是否被删,以及pk没有对应的对象 # 假设pk3被删,pk100没有 => [obj1] + [{...}] # 注:必定不要在循环体中对循环对象进行增删(影响对象长度)的操做 obj_list = [] data_list = [] for dic in request_data: # request_data多是list,单内部不必定是dict try: pk = dic.pop('pk') try: obj = models.Book.objects.get(pk=pk, is_delete=False) obj_list.append(obj) data_list.append(dic) except: pass except: return APIResponse(1, 'data error', http_status=400) book_ser = serializers.BookModelSerializer(instance=obj_list, data=data_list, many=True, partial=True) book_ser.is_valid(raise_exception=True) book_obj_list = book_ser.save() return APIResponse(results=serializers.BookModelSerializer(book_obj_list, many=True).data)
# 单改 def _single_update(self, pk, data): try: instance = models.Worker.objects.get(pk=pk, is_delete=False) ser = serializers.WorkerModelSerializer(instance=instance, data=data, partial=True) ser.is_valid(raise_exception=True) obj = ser.save() return APIResponse(data=serializers.WorkerModelSerializer(obj).data) except: return APIResponse(1, 'pk error', http_status=400)
# 群改 def _many_updata(self, data): instance_list = [] data_list = [] for dic in data: try: # 不是字典,数据错误 pk = dic.pop('pk') if len(dic) == 0: raise Exception('随便') try: # pk没有,对应的obj没有,对应的obj已删除,该数据丢弃 obj = models.Worker.objects.get(pk=pk, is_delete=False) instance_list.append(obj) data_list.append(dic) except: pass except: return APIResponse(1, 'data error', http_status=400) ser = serializers.WorkerModelSerializer(instance=instance_list, data=data_list, partial=True, many=True) ser.is_valid(raise_exception=True) obj_list = ser.save() return APIResponse(data=serializers.WorkerModelSerializer(obj_list, many=True).data)
def patch(self, request, *args, **kwargs): pk = kwargs.get('pk') request_data = request.data if pk and isinstance(request_data, dict) and len(request_data) != 0: return self._single_update(pk, request_data) elif not pk and isinstance(request_data, list) and len(request_data) != 0: return self._many_updata(request_data) else: return APIResponse(1, 'data error', http_status=400)