drf序列化高级、自定义只读只写、序列化覆盖字段、二次封装Response、数据库查询优化(断关联)、十大接口、视图家族、自动补全图片链接
辜老板 人气:2目录
- 自定义只读
- 自定义只写
- 序列化覆盖字段
- 二次封装Response
- 数据库关系分析
- 断外键关联关系
- ORM操作外键关系
- ORM四种关联关系
- 基表
- 系列化类其他配置(了解)
- 十大接口
- BaseSerializer初始化方法
- 十大接口序列化总结
- 单查群查
- 单增群增
- 单删群删
- 单整体改/群整体改
- 单局部改/群局部改
- 群增群改配置
- 十大接口小结
- 字段提供就校验,不提供拉到
- DjangoORM内置优化机制:一次最多查21条数据
- models.py
- response.py
- serializers.py
- urls.py
- 视图家族
- 视图基类 APIView、GenericAPIView
- 基于GenericAPIView的十大接口
- 视图工具类:mixins包
- 工具视图类 generics工具包:继承指定类
- 工具
- 基于generics包下工具视图类的六大基础接口
- 视图集(开发常用,最高级)
- 路由组件(繁琐,可以自定义映射关系)
- 路由组件(简化)
- 视图组件 views.py
- 重写删除方法:destroy
- 群删接口
- 视图级使用总结
- 自定义路由组件(了解)
- 上传文件接口
- 视图基类 APIView、GenericAPIView
自定义只读
自定义只读:Model类中
@property
def 字段(self): return "字段值"
models.py
class Book(BaseModel):
name = models.CharField(max_length=64)
price = models.DecimalField(max_digits=5, decimal_places=2, null=True)
image = models.ImageField(upload_to='img', default='imghttps://img.qb5200.com/download-x/default.png')
publish = models.ForeignKey(to='Publish', related_name='books', db_constraint=False, on_delete=models.DO_NOTHING)
authors = models.ManyToManyField(to='Author', related_name='books', db_constraint=False)
@property # @property字段默认就是read_only,且不允许修改
def publish_name(self):
return self.publish.name
自定义只写
自定义只写:Serializer类中
字段 = serializers.字段类型(write_only=True)
serializers.py
class BookModelSerializer(serializers.ModelSerializer):
class Meta:
list_serializer_class = BookListSerializer
model = models.Book
fields = ['name', 'price', 'image', 'publish', 'authors', 'publish_name', 'author_list']
extra_kwargs = {
'publish': {
'write_only': True
}
序列化覆盖字段
覆盖字段:Serializer类中,规则在()中规定,可以是只读、只写、可读可写任何形式
系统同名字段 = serializers.字段类型()
# 如何覆盖外键字段
publish = serializers.PrimaryKeyRelatedField(read_only=True) # 只读
# publish = serializers.PrimaryKeyRelatedField(queryset=models.Publish.objects.all(), write_only=True) # 只写
# publish = serializers.PrimaryKeyRelatedField(queryset=models.Publish.objects.all()) # 可读可写
# publish = serializers.PrimaryKeyRelatedField(queryset=models.Publish.objects.all())
# authors = serializers.PrimaryKeyRelatedField(queryset=models.Author.objects.all(), many=True)
class Meta:
model = models.Book
fields = ('name', 'publish', )
extra_kwargs = {
'publish': { # 系统原有的外键字段,要留给反序列化过程使用,序列化外键内容,用@property自定义
'write_only': True,
},
二次封装Response
from rest_framework.response import Response
class APIResponse(Response):
def __init__(self, status=0, msg='ok', http_status=None, headers=None, exception=False, **kwargs):
data = {
'status': status,
'msg': msg
}
# 在外界可以存值
if kwargs:
data.update(kwargs)
super().__init__(data=data, status=http_status, headers=headers, exception=exception)
数据库关系分析
"""
1)之间有关系的两个表,增删改操作会相互影响(效率低),查询操作就是正常的连表操作
2)之间有关系的两个表,断开关联,但所有数据保持与原来一致
每个表都可以单独操作,增删改操作效率极高,但是容易出现脏数据(开发中完全可以避免)
由于数据没有任何变化,所以查询的连表操作不会受到任何影响
3)Django的ORM支持断关联操作关系表,且所有的操作方式和没有断关联操作一致
"""
断外键关联关系
有关联的表,如果直接存在关联关系(外键),增删改操作效率低(但是安全);删除外键(断关联),可以提高增删改操作效率,但是要手动处理数据安全问题(避免脏数据的参数)
db_constraint=False
eg:
# 关系字段
brand = models.ForeignKey(to='Brand', related_name='Cars', db_constraint=False)
sponsors = models.ManyToManyField(to="Sponsor", related_name="Cars", db_constraint=False)
ORM操作外键关系
外键位置:
"""
外键位置:
1)一对多:ForeignKey必须放在多的一方,书与出版社,外键应该放在书表
2)多对多:ManyToManyField放在任何一方都可以,因为会创建关系表,在关系表中用两个外键分别关联两个表
3)一对一:OneToOneField放在依赖的表,作者与作者详情,放在详情表,OneToOneField会被转换为 外键 + 唯一约束
"""
外键操作:
ForeignKey可以设置:related_name, db_constraint, on_delete
OneToOneField可以设置:related_name, db_constraint, on_delete
ManyToManyField只能设置:related_name, db_constraint
不能设置on_delete的原因:不管是关联的A表,还是B表,数据修改,都会影响到关系表(默认级联),
如果想控制,只能自定义关系表,在关系表的两个外键分别设置on_delete
参数含义:
related_name:表之间反向访问的名字,默认是 表名小写|表名小写_set
db_constraint:表之间的关联关系,默认为True,代表关联,设置False,可以提高增删改的效率,且不影响查等
on_delete:表之间级联更新,在django 1.x下默认是CASCADE(级联更新),在django 2.x下必须手动明确
DO_NOTHING(级联不更新)
案例:
"""
表关系:
作者没,作者详情一定没:CASCADE *****
作者没,书还是该作者出的:DO_NOTHING
部门们,部门内的员工全部进入未分组部门:SET_DEFAULT (需要配合default属性使用)
部门们,部门内的员工部门外键字段设置为空:SET_NULL (需要配合null=True属性使用) *****
"""
class Author(models.Model):
name = models.CharField(max_length=64)
class AuthorDetail(models.Model):
phone = models.CharField(max_length=11)
author = models.OneToOneField(
to=Author,
related_name='detail',
db_constraint=False,
on_delete=models.SET_NULL,
null=True
)
ORM四种关联关系
级联、不处理、置为默认值(配合默认值)、置空(配合可以为空)
基表
# 基类:是抽象的(不会完成数据库迁移),目的是提供共有字段的
# 抽出来的基类
class BaseModel(models.Model):
name = models.CharField(max_length=64)
is_delete = models.BooleanField(default=0)
updated_time = models.DateTimeField(auto_now=True)
class Meta:
abstract = True # 必须完成该配置
class Car(BaseModel):
pass
# 其他的表继承了基类就有基类的属性了
系列化类其他配置(了解)
class AuthorModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Author
# 不常用,将全部字段提供给外界
fields = '__all__'
# ------------------------------------------------------------------
class AuthorModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Author
# 不常用,非,排除指定字段的其他所有字段,不能自动包含 外键反向 字段
exclude = ['is_delete', 'updated_time']
# ------------------------------------------------------------------
class AuthorModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Author
# 'detail', 'books' 是 外键(正向|反向) 字段
fields = ['name', 'detail', 'books']
# 不常用,自动深度,自动深度会显示外键关联表的所有字段
depth = 2
# 正向外键字段:就是外键的属性名
# 反向外键字段:就是外键属性设置的related_name
十大接口
BaseSerializer初始化方法
from rest_framework.serializers import BaseSerializer
def __init__(self, instance=None, data=empty, **kwargs):
self.instance = instance
if data is not empty:
self.initial_data = data
self.partial = kwargs.pop('partial', False)
self._context = kwargs.pop('context', {})
kwargs.pop('many', None)
super().__init__(**kwargs)
'''
instance:赋值对象的
data:赋值数据的
many:数据是单个还是多个
partial:在修改需求时使用,可以将所有校验字段required校验规则设置为False
context:用于视图类和序列化类直接传参使用
'''
十大接口序列化总结
六个必备:单查、群查、单增、单删、单整体改(了解),单局部该
四个额外接口:群增、群删、群整体改、群局部改
# 常见使用
# 单查接口 get请求
UserModelSerializer(instance=user_obj)
# 群查接口 get请求
UserModelSerializer(instance=user_query, many=True)
# 单增接口,request.data是字典 post请求
UserModelSerializer(data=request.data)
# 群增接口,request.data是列表 post请求
UserModelSerializer(data=request.data, many=True)
# 单整体改接口,request.data是字典 put请求
UserModelSerializer(instance=user_obj, data=request.data)
# 群整体改接口,request.data是列表,且可以分离出pks,转换成user_queryset put请求
UserModelSerializer(instance=user_queryset, data=request.data, many=True)
# 单局部改接口,request.data是字典 patch请求
UserModelSerializer(instance=user_obj, data=request.data, partial=True)
# 群局部改接口,request.data是列表,且可以分离出pks,转换成user_queryset patch请求
UserModelSerializer(instance=user_queryset, data=request.data, partial=True, many=True)
# 删接口,用不到序列化类 delete请求
models.Car.objects.filter(is_delete=False, pk__in=pks).update(is_delete=True)
单查群查
判断有无pk
class CarAPIView(APIView):
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk: # 单查
try:
obj = models.Car.objects.get(pk=pk)
serializer = serializers.CarModelSerializer(obj)
return APIResponse(result=serializer.data)
except:
return APIResponse(status=1, msg='pk error', http_status=status.HTTP_400_BAD_REQUEST, exception=True)
else: # 群查
queryset = models.Car.objects.all()
serializer = serializers.CarModelSerializer(queryset, many=True)
return APIResponse(results=serializer.data)
单增群增
判断数据类型是否为列表
def post(self, request, *args, **kwargs):
# 单增
if not isinstance(request.data, list):
# 单增
serializer = serializers.CarModelSerializer(data=request.data)
serializer.is_valid(raise_exception=True) # 如果校验失败,直接抛异常,返回给前台
car_obj = serializer.save()
return APIResponse(
result=serializers.CarModelSerializer(car_obj).data,
status=status.HTTP_201_CREATED
)
else:
# 群增
serializer = serializers.CarModelSerializer(data=request.data,many=True)
serializer.is_valid(raise_exception=True) # 如果校验失败,直接抛异常,返回给前台
objs = serializer.save()
return APIResponse(result=serializers.CarModelSerializer(objs, many=True).data, http_status=201)
单删群删
判断前端传过来的数据:是url参数就是单删,是data数据就是群删
只是更改了表示是否删除的字段
# 单删群删
"""
单删:接口:/books/(pk)/
群删:接口:/books/ 数据:[pk1, ..., pkn]
"""
def delete(self,request, *args,**kwargs):
pk = kwargs.get('pk')
if pk:
pks = [pk] # [1] 单删
else:
pks = request.data # [2,3,4] 群删
try:
rows = models.Car.objects.filter(is_delete=False, pk__in=pks).update(is_delete=True)
except:
return APIResponse(1, '数据有误')
if rows:
return APIResponse(0, '删除成功')
return APIResponse(2, '删除失败')
单整体改/群整体改
# 单整体改群整体改
"""
单整体改:接口:/books/(pk)/ 数据:dict
群整体改:接口:/books/ 数据:[{pk1, ...}, ..., {pkn, ...}] | {pks: [pk1, ..., pkn], data: [{}, ..., {}]}
"""
def put(self,request, *args, **kwargs):
pk = kwargs.get('pk')
if pk: # 单
try:
instance = models.Car.objects.get(is_delete=False, pk=pk)
except:
return APIResponse(1,'pk error', http_status=400)
serializer = serializers.CarModelSerializer(instance=instance, data=request.data)
serializer.is_valid(raise_exception=True)
obj = serializer.save() # 返回的是受影响的对象
return APIResponse(result=serializers.CarModelSerializer(obj).data)
else: # 群
pks = []
try:
for dic in request.data:
pks.append(dic.pop('pk'))
objs = models.Car.objects.filter(is_delete=False, pk__in=pks) # 筛选 __in(或),双下线方法
assert len(objs) == len(request.data) # 两个列表长度必须一致 断言方法
except:
return APIResponse(1, '数据有误', http_status=400)
serializer = serializers.CarModelSerializer(instance=objs, data=request.data, many=True)
serializer.is_valid(raise_exception=True)
objs = serializer.save()
return APIResponse(result=serializers.CarModelSerializer(objs, many=True).data)
单局部改/群局部改
# 单局部改群局部改
"""
单局部改:接口:/books/(pk)/ 数据:dict
群局部改:接口:/books/ 数据:[{pk1, ...}, ..., {pkn, ...}] | {pks: [pk1, ..., pkn], data: [{}, ..., {}]}
"""
def patch(self,request, *args, **kwargs):
pk = kwargs.get('pk')
if pk: # 单
try:
instance = models.Car.objects.get(is_delete=False, pk=pk)
except:
return APIResponse(1, 'pk error', http_status=400)
# partial=True就是将所有反序列化字段的 required 设置为 False(提供就校验,不提供不校验)
serializer = serializers.CarModelSerializer(
instance=instance,
data=request.data,
partial=True
)
serializer.is_valid(raise_exception=True)
obj = serializer.save()
return APIResponse(result=serializers.CarModelSerializer(obj).data)
else:
pks = []
try:
for dic in request.data:
pks.append(dic.get('pk'))
objs = models.Car.objects.filter(is_delete=False, pk__in=pks)
assert len(objs) == len(request.data)
except:
return APIResponse(1, '数据有误', http_status=400)
serializer = serializers.CarModelSerializer(
instance=objs,
data=request.data,
many=True,
partial=True,
)
serializer.is_valid(raise_exception=True)
objs = serializer.save()
return APIResponse(result=serializers.CarModelSerializer(objs, many=True).data)
群增群改配置
serializers.py:
# 群增群改辅助类(了解)
class BookListSerializer(serializers.ListSerializer):
"""
1)create群增方法不需要重新
2)update群改方法需要重写,且需要和views中处理request.data的逻辑配套使用
3)self.child就代表该ListSerializer类绑定的ModelSerializer类
BookListSerializer的self.child就是BookModelSerializer
"""
# 重写update方法
def update(self, queryset, validated_data_list):
return [
self.child.update(queryset[index], validated_data) for index, validated_data in enumerate(validated_data_list)
]
class CarModelSerializer(serializers.ModelSerializer):
class Meta:
# 配置自定义群增群改序列化类
list_serializer_class = BookListSerializer
十大接口小结
"""
1)初始化序列化类,设置partial=True可以将所有反序列化字段的 required 设置为 False(提供就校验,不提供不校验),可以运用在局部修改接口
2)初始化序列化类,设置context={...},在序列化类操作self.context,实现视图类和序列化类数据互通
3)只有要完成资源的群改这种特殊需求时,才需要自定义ListSerializer绑定给自定义的ModelSerializer,重写update方法,来完成需求
"""
字段提供就校验,不提供拉到
实现单局部该/群局部改
'required':False
# partial=True就是将所有反序列化字段的 required 设置为 False(提供就校验,不提供不校验)
DjangoORM内置优化机制:一次最多查21条数据
queryset = models.Book.objects.filter(is_delete=False).all()
models.py
from django.db import models
# 抽出来的基类
class BaseModel(models.Model):
name = models.CharField(max_length=64)
is_delete = models.BooleanField(default=0)
updated_time = models.DateTimeField(auto_now=True)
class Meta:
abstract = True
class Car(BaseModel):
price = models.DecimalField(max_digits=9, decimal_places=2)
# 关系字段
brand = models.ForeignKey(to='Brand', related_name='Cars', db_constraint=False)
sponsors = models.ManyToManyField(to="Sponsor", related_name="Cars", db_constraint=False)
class Meta:
verbose_name_plural = '汽车表'
def __str__(self):
return self.name
def brand_(self):
return self.brand.name
# 多对多跨表查询
def sponsors_(self):
temp_sponsor_list = []
for sponsor in self.sponsors.all():
sponsor_dic = {"name": sponsor.name}
try:
sponsor_dic['电话'] = sponsor.detail.phone
except:
sponsor_dic['电话'] = ''
temp_sponsor_list.append(sponsor_dic)
return temp_sponsor_list
class Brand(BaseModel):
class Meta:
verbose_name_plural = '品牌表'
def __str__(self):
return self.name
# 一对多跨表查询
def car_list(self):
temp_car_list = []
for car_obj in self.Cars.all():
car_dic = {
"name": car_obj.name
}
try:
car_dic['price'] = car_obj.price
except:
car_dic['price'] = ''
temp_car_list.append(car_dic)
return temp_car_list
class Sponsor(BaseModel):
class Meta:
verbose_name_plural = '赞助商表'
def __str__(self):
return self.name
class SponsorDetail(models.Model):
class Meta:
verbose_name_plural = '赞助商详情表'
phone = models.CharField(max_length=11)
is_delete = models.BooleanField(default=1)
updated_time = models.DateTimeField(auto_now=True)
sponsor = models.OneToOneField(to="Sponsor", related_name="detail", db_constraint=False)
response.py
from rest_framework.response import Response
class APIResponse(Response):
def __init__(self, status=0, msg='ok', http_status=None, headers=None, exception=False, **kwargs):
data = {
'status': status,
'msg': msg
}
# 在外界可以存值
if kwargs:
data.update(kwargs)
super().__init__(data=data, status=http_status, headers=headers, exception=exception)
serializers.py
from rest_framework import serializers
from rest_framework import exceptions
from . import models
# 群增群改辅助类(了解)
class BookListSerializer(serializers.ListSerializer):
"""
1)create群增方法不需要重新
2)update群改方法需要重写,且需要和views中处理request.data的逻辑配套使用
3)self.child就代表该ListSerializer类绑定的ModelSerializer类
BookListSerializer的self.child就是BookModelSerializer
"""
# 重写update方法
def update(self, queryset, validated_data_list):
return [
self.child.update(queryset[index], validated_data) for index, validated_data in enumerate(validated_data_list)
]
class CarModelSerializer(serializers.ModelSerializer):
def validate(self, attrs):
print(self.context) # 可以获得视图类在初始化序列化对象时传入的context
# self.context.update({'a': 10}) # 序列化类内部更新context,传递给视图类
return attrs
class Meta:
# 配置自定义群增群改序列化类
list_serializer_class = BookListSerializer
model = models.Car
fields = ['name', 'is_delete', 'price', 'brand', 'brand_', 'updated_time', 'sponsors_']
extra_kwargs = {
'brand': {
'write_only': True,
}
# 'name':{
# 'required':False
# },
# 'price': {
# 'required': False
# },
}
class BrandModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Brand
fields = ['name', 'is_delete', 'updated_time', 'car_list']
urls.py
from django.conf.urls import url
from . import views
from django.views.static import serve
from d_car import settings
urlpatterns = [
url(r'v1/car/$', views.CarAPIView.as_view()),
url(r'v1/car/(?P<pk>\d+)/$', views.CarAPIView.as_view()),
url(r'brand/$', views.BrandAPIView.as_view()),
url(r'brand/(?P<pk>\d+)/$', views.BrandAPIView.as_view()),
url(r'v2/car/$', views.CarV2APIView.as_view()),
url(r'v2/car/(?P<pk>\d+)/$', views.CarV2APIView.as_view()),
# url(r'v3/car/$', views.CarV3APIView.as_view()),
# url(r'v3/car/(?P<pk>\d+)/$', views.CarV3APIView.as_view()),
# 暴露文件夹
url(r'^media/(?P<path>.*)', serve, {'document_root': settings.MEDIA_ROOT}),
]
视图家族
"""
视图基类:APIView、GenericAPIView
视图工具类:mixins包下的五个类(六个方法)
工具视图类:generics包下的所有GenericAPIView的子类
视图集:viewsets包下的类
"""
""" GenericAPIView基类(基本不会单独使用,了解即可,但是是高级视图类的依赖基础)
1)GenericAPIView继承APIView,所有APIView子类写法在继承GenericAPIView时可以保持一致
2)GenericAPIView给我们提供了三个属性 queryset、serializer_class、lookup_field
3)GenericAPIView给我们提供了三个方法 get_queryset、get_serializer、get_obj
"""
""" mixins包存放了视图工具类(不能单独使用,必须配合GenericAPIView使用)
CreateModelMixin:单增工具类
create方法
ListModelMixin:群查工具类
list方法
RetrieveModelMixin:单查工具类
retrieve方法
UpdateModelMixin:单整体局部改工具类
update方法
DestroyModelMixin:单删工具类
destory方法
"""
""" generics包下的所有GenericAPIView的子类(就是继承GenericAPIView和不同mixins下的工具类的组合)
1)定义的视图类,继承generics包下已有的特点的GenericAPIView子类,可以在只初始化queryset和serializer_class两个类属性后,就获得特定的功能
2)定义的视图类,自己手动继承GenericAPIView基类,再任意组合mixins包下的一个或多个工具类,可以实现自定义的工具视图类,获得特定的功能或功能们
注:
i)在这些模式下,不能实现单查群查共存(可以加逻辑区分,也可以用视图集知识)
ii)DestroyModelMixin工具类提供的destory方法默认是从数据库中删除数据,所以一般删除数据的需求需要自定义逻辑
"""
视图基类 APIView、GenericAPIView
视图基类:APIView、GenericAPIView
i)继承APIView的,所以拥有APIView的全部
ii)三个类属性:queryset、serializer_class、lookup_field
iii)三个方法:get_queryset、get_serializer、get_object
过渡:单独继承GenericAPIView类的视图类,需要自己定义请求方法如get,还需要属性方法体完成请求
定义的视图类,自己手动继承GenericAPIView基类,再任意组合mixins包下的一个或多个工具类,可以实现自定义的工具视图类,获得特定的功能或功能们
# ----------------------------- 过渡写法:了解 -----------------------------
from rest_framework.generics import GenericAPIView
class BookV1APIView(GenericAPIView):
# 将数据和序列化提示为类属性,所有的请求方法都可以复用
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
lookup_field = 'pk' # 可以省略,默认是pk,与url有名分组对应的
# 群查
def get(self, request, *args, **kwargs):
# queryset = models.Book.objects.filter(is_delete=False).all() # => 方法+属性两行代码
queryset = self.get_queryset()
# serializer = serializers.BookModelSerializer(instance=queryset, many=True) # => 方法+属性两行代码
serializer = self.get_serializer(instance=queryset, many=True)
return APIResponse(results=serializer.data)
# 单查
# def get(self, request, *args, **kwargs):
# obj = self.get_object()
# serializer = self.get_serializer(obj)
# return APIResponse(results=serializer.data)
# 单增
def post(self, request, *args, **kwargs):
# serializer = serializers.BookModelSerializer(data=request.data)
serializer = self.get_serializer(data=request.data) # 同样的步骤多了,好处就来了
serializer.is_valid(raise_exception=True)
obj = serializer.save()
return APIResponse(result=self.get_serializer(obj).data, http_status=201)
基于GenericAPIView的十大接口
views.py:
# 十大接口:
# 1)单查、群查、单增、单整体改、单局部改都可以直接使用
# 2)单删不能直接使用,因为默认提供的功能是删除数据库数据,不是我们自定义is_delete字段值修改
# 3)除了群查以为的接口,都要自己来实现
# 注:给序列化类context赋值{'request': request},序列化类就可以自动补全后台图片链接
from rest_framework.generics import GenericAPIView
from rest_framework import mixins
from . import models, serializers
from rest_framework.response import Response
class BookV1APIView(GenericAPIView,
mixins.RetrieveModelMixin,
mixins.ListModelMixin,
mixins.CreateModelMixin,
mixins.UpdateModelMixin):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
def get(self, request, *args, **kwargs):
if 'pk' in kwargs:
return self.retrieve(request, *args, **kwargs) # 单查
# queryset = models.Book.objects.filter(is_delete=False).all()
# 注:给序列化类context赋值{'request': request},序列化类就可以自动补全后台图片链接
# serializer = serializers.BookModelSerializer(queryset, many=True, context={'request': request})
# return Response(serializer.data)
return self.list(request, *args, **kwargs) # 群查
def post(self, request, *args, **kwargs):
if not isinstance(request.data, list):
return self.create(request, *args, **kwargs)
serializer = self.get_serializer(data=request.data, many=True)
serializer.is_valid(raise_exception=True)
self.perform_create(serializer)
headers = self.get_success_headers(serializer.data)
return Response(serializer.data, status=201, headers=headers)
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
pks = [pk]
else:
pks = request.data
try:
rows = models.Book.objects.filter(is_delete=False, pk__in=pks).update(is_delete=True)
except:
return Response(status=400)
if rows:
return Response(status=204)
return Response(status=400)
def put(self, request, *args, **kwargs):
if 'pk' in kwargs:
return self.update(request, *args, **kwargs)
pks = []
try:
for dic in request.data:
pks.append(dic.pop('pk'))
objs = models.Book.objects.filter(is_delete=False, pk__in=pks)
assert len(objs) == len(request.data)
except:
return Response(status=400)
serializer = serializers.BookModelSerializer(instance=objs, data=request.data, many=True)
serializer.is_valid(raise_exception=True)
objs = serializer.save()
return Response(serializers.BookModelSerializer(objs, many=True).data)
def patch(self, request, *args, **kwargs):
if 'pk' in kwargs:
return self.partial_update(request, *args, **kwargs)
pks = []
try:
for dic in request.data:
pks.append(dic.pop('pk'))
objs = models.Book.objects.filter(is_delete=False, pk__in=pks)
assert len(objs) == len(request.data)
except:
return Response(status=400)
serializer = serializers.BookModelSerializer(instance=objs, data=request.data, many=True, partial=True)
serializer.is_valid(raise_exception=True)
objs = serializer.save()
return Response(serializers.BookModelSerializer(objs, many=True).data)
视图工具类:mixins包
from rest_framework import mixins
""" mixins包存放了视图工具类(不能单独使用,必须配合GenericAPIView使用)
CreateModelMixin:单增工具类
create方法
ListModelMixin:群查工具类
list方法
RetrieveModelMixin:单查工具类
retrieve方法
UpdateModelMixin:单整体局部改工具类
update方法
DestroyModelMixin:单删工具类
destory方法
"""
# ----------------------------- 过渡写法:了解 -----------------------------
from rest_framework.generics import GenericAPIView
from rest_framework import mixins
class BookV2APIView(GenericAPIView, mixins.RetrieveModelMixin, mixins.CreateModelMixin):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
# 单查
def get(self, request, *args, **kwargs):
# obj = self.get_object()
# serializer = self.get_serializer(obj)
# return APIResponse(results=serializer.data)
# return self.retrieve(request, *args, **kwargs)
response = self.retrieve(request, *args, **kwargs)
return APIResponse(result=response.data)
# 单增
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
# ----------------------------- 开发写法:常用 -----------------------------
from rest_framework.generics import RetrieveAPIView
class BookV3APIView(RetrieveAPIView):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
# 单查
pass
工具视图类 generics工具包:继承指定类
generics包:工具视图类
i)系统完成的GenericAPIView与mixins包下工具类的不同组合
只需要配置三个类属性
ii)自己完成GenericAPIView与mixins包下工具类的不同组合
需要配置三个类属性,需要书写请求方法,如post,内部直接调用self.create方法
iii)自己继承一堆generics包下的工具视图,完成组合
只需要配置三个类属性,但是单查、群查不能共存
工具
继承指定的类,完成相应的功能
from rest_framework import generics 点进去看看又那些类
RetrieveAPIView : 单查 内部:get 方法写好了
ListAPIView :群查 内部:get 方法写好了
CreateAPIView :单增 内部:post 方法
DestroyAPIView : 单删 内部:delete 方法写好了
UpdateAPIView : 单整体改,单局部改 内部:put、patch 方法写好了
ListCreateAPIView : 群查,和单增 内部: get、post 方法写好了
ListCreateAPIView : 群增 内部:post方法
。。。
单查:
from rest_framework.generics import RetrieveAPIView
class BookV3APIView(RetrieveAPIView):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
# 单查 RetrieveAPIView内部已经写好了get方法
pass
基于generics包下工具视图类的六大基础接口
六个必备:单查、群查、单增、单删、单整体改(了解),单局部该
四个额外接口:群增、群删、群整体改、群局部改
# 六大基础接口
# 1)直接继承generics包下的工具视图类,可以完成六大基础接口
# 2)单查群查不能共存,因为都是get方法
# 3)单删一般会重写
views.py:
from . import models, serializers
from rest_framework.response import Response
from rest_framework import generics
class BookV2APIView(generics.ListAPIView,
generics.RetrieveAPIView,
generics.CreateAPIView,
generics.UpdateAPIView,
generics.DestroyAPIView):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
def get(self, request, *args, **kwargs): # 重写单查群查的get
if 'pk' in kwargs:
return self.retrieve(request, *args, **kwargs)
return self.list(request, *args, **kwargs)
def delete(self, request, *args, **kwargs): # 重写删除(不是真的删除数据,是修改字段)
pk = kwargs.get('pk')
models.Book.objects.filter(is_delete=False, pk=pk).update(is_delete=True)
return Response(status=204)
视图集(开发常用,最高级)
路由组件(繁琐,可以自定义映射关系)
urls.py
url(r'^v3/books/$', views.BookV3APIView.as_view(
{'get': 'list', 'post': 'create', 'delete': 'multiple_destroy'}
)),
url(r'^v3/books/(?P<pk>\d+)/$', views.BookV3APIView.as_view(
{'get': 'my_list'}
)),
views.py
from rest_framework.viewsets import ModelViewSet
from rest_framework.response import Response
class BookV3APIView(ModelViewSet):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
# 可以在urls.py中as_view({'get': 'my_list'})自定义请求映射
def my_list(self, request, *args, **kwargs):
return Response('ok')
路由组件(简化)
urls.py
from django.conf.urls import url, include
from . import views
# 路由组件,必须配合视图集使用
from rest_framework.routers import SimpleRouter
router = SimpleRouter()
# 以后就写视图集的注册即可:BookV3APIView和BookV4APIView都是视图集
router.register('v3/books', views.BookV3APIView, 'book')
router.register('v4/books', views.BookV4APIView, 'book')
urlpatterns = [
url('', include(router.urls))
]
视图组件 views.py
from rest_framework.viewsets import ReadOnlyModelViewSet
class BookV4APIView(ReadOnlyModelViewSet):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookModelSerializer
重写删除方法:destroy
因为继承的删除方法:是真的删除了数据
我们修改的:修改is_delete字段
# 需要完成字段删除,不是重写delete方法,而是重写destroy方法
def destroy(self, request, *args, **kwargs):
pk = kwargs.get('pk')
models.Book.objects.filter(is_delete=False, pk=pk).update(is_delete=True)
return Response(status=204)
群删接口
# 群删接口
def multiple_destroy(self, request, *args, **kwargs):
try:
models.Book.objects.filter(is_delete=False, pk__in=request.data).update(is_delete=True)
except:
return Response(status=400)
return Response(status=204)
视图级使用总结
六个必备:单查、群查、单增、单删、单整体改(了解),单局部该
四个额外接口:群增、群删、群整体改、群局部改
# 注:给序列化类context赋值{'request': request},序列化类就可以自动补全后台图片链接
"""
视图集的使用总结
1)可以直接继承ModelViewSet,实现六大继承接口(是否重写destroy方法,或其他方法,根据需求决定)
2)可以直接继承ReadOnlyModelViewSet,实现只读需求(只有单查群查)
3)继承ViewSet类,与Model类关系不是很密切的接口:登录的post请求,是查询操作;短信验证码发生接口,借助第三方平台
4)继承GenericViewSet类,就代表要配合mixins包,自己完成任意组合
5)继承以上4个视图集任何一个,都可以与路由as_view({映射})配合,完成自定义请求响应方法
"""
自定义路由组件(了解)
from rest_framework.routers import SimpleRouter as DrfSimpleRouter
from rest_framework.routers import Route, DynamicRoute
class SimpleRouter(DrfSimpleRouter):
routes = [
# List route.
Route(
url=r'^{prefix}{trailing_slash}$',
mapping={
'get': 'list',
'post': 'create', # 注:群增只能自己在视图类中重写create方法,完成区分
'delete': 'multiple_destroy', # 新增:群删
'put': 'multiple_update', # 新增:群整体改
'patch': 'multiple_partial_update' # 新增:群局部改
},
name='{basename}-list',
detail=False,
initkwargs={'suffix': 'List'}
),
# Dynamically generated list routes. Generated using
# @action(detail=False) decorator on methods of the viewset.
DynamicRoute(
url=r'^{prefix}/{url_path}{trailing_slash}$',
name='{basename}-{url_name}',
detail=False,
initkwargs={}
),
# Detail route.
Route(
url=r'^{prefix}/{lookup}{trailing_slash}$',
mapping={
'get': 'retrieve',
'put': 'update',
'patch': 'partial_update',
'delete': 'destroy'
},
name='{basename}-detail',
detail=True,
initkwargs={'suffix': 'Instance'}
),
# Dynamically generated detail routes. Generated using
# @action(detail=True) decorator on methods of the viewset.
DynamicRoute(
url=r'^{prefix}/{lookup}/{url_path}{trailing_slash}$',
name='{basename}-{url_name}',
detail=True,
initkwargs={}
),
]
上传文件接口
urls.py
from django.conf.urls import url, include
from . import views
# 路由组件,必须配合视图集使用
from rest_framework.routers import SimpleRouter
router = SimpleRouter()
# /books/image/(pk) 提交 form-data:用image携带图片
router.register('books/image', views.BookUpdateImageAPIView, 'book')
urlpatterns = [
url('', include(router.urls))
]
serializers.py
class BookUpdateImageModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Book
fields = ['image']
views.py
# 上次文件 - 修改头像 - 修改海报
from rest_framework.viewsets import GenericViewSet
from rest_framework import mixins
class BookUpdateImageAPIView(GenericViewSet, mixins.UpdateModelMixin):
queryset = models.Book.objects.filter(is_delete=False).all()
serializer_class = serializers.BookUpdateImageModelSerializer
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