drf表操作
一、面向对象二次封装Response
为方便多次调用Response方法，可将Response进行二次封装
response.py:
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)
views.py:
class BookAPIView(APIview):
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
book_obj = models.Book.bojects.filter(pk=pk).first()
if not boot_obj:
# 以下内容被封装
# return Response({
# 'status': 1,
# 'msg': 'pk error'
# }, status=400)
return APIResponse(1, 'pk error', http_static=400)
book_data = serializers.BookModelSerializer(book_obj).data
# return Response({
# 'status': 0,
# 'msg': 'ok',
# 'results': car_data
# })
return APIResponse(results=book_data)
二、模型基表
Model类的内部配置Meta类要设置abstract=True，这样的Model类就是用来作为基表。
models.py:
class BookModel(models.Model):
is_delete = models.BooleanField(default=False)
create_time = models.DateField(auto_now_add=Ture)
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 = Ture
三、多表ORM关联操作
3.1 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
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
models.py:
class Book(BaseModel):
name = models.CharField(max_length=16)
price = models.DecimalField(max_digits=5, decimal_places=2)
publish = models.ForeignKey(to='Publish', related_name='books', db_constraint=False, on_delete=models.DO_NOTHING)
# 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
# ManyToManyField字段不提供设置on_delete，如果想设置关系表级联，只能手动定义关系表
author = models.ManyToManyField(to='Author', related_name='books', db_constraint=False)
# 自定义连表深度，不需要反序列化，因为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)
sex = models.IntegerField(choices=[(0,'男'),(1,'女')], default=0)
class AuthorDetail(BaseModel):
mobile = models.CharField(max_length=11)
# 有作者可以没有详情，删除作者，详情一定会被级联删除
# 外键字段为正向查询字段，related_name是反向查询字段
autor = models.OneToOneField(to='Author', related_name='detail', db_constraint=False, on_delete=models.CASCADE)
3.2 ORM外键设计
1、一对多：外键放在多的一方
2、多对多：外键放在常用的一方
3、一对一：外键放在不常用的一方
4、外键字段为正向查询字段，related_name是反向查询字段
四、连表序列化
serializers.py：
class BookListSerializer(serializers.ListSerializer):
# 1、create方法父级ListSerializer已经提供了
# 2、父级ListSerializer没有通过update方法的实现体，需要重写
def update(self, instance, validated_data):
return [
self.child.update(instance[i],attrs) for i,attrs in enumerate(validated_data)
]
class BookModelSerializer(serializers.ListSerializer)
# 通过BookModelSerializer.Meta.list_serializer_class来访问绑定的ListSerializer
class Meta:
list_serializer_class = BookListSerializer
model = moldes.Book
# 序列化反序列化整合
fields = ('name', 'price', 'publish_name', 'author_list', 'publish', 'authors')
extra_kwargs = {
'publish': {
'wite_only': Ture
},
'authors': {
'wite_only': Ture
}
}
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，外键数据是唯一：many=False；不唯一：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
field = ('name', 'address', 'books')
五、单查群查序列化
views.py:
class BookAPIView(APIView):
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)
六、单删群删接口
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
pks = [pk]
else:
pks = request.data.get('pks')
if not pks:
return APIResponse(1, 'delete error', http_status=400)
rows = models.Book.objects.filter(is_delete=False, pk__in=pks).update(is_delete=Ture)
if rows:
return APIResponse(0,'delete ok')
return APIResponse(1, 'delete failed')
七、单增群增接口
def post(self, request, *args, **kwargs):
request_data = request.data
# 单增
if isinstance(request_data, dict)
book_ser = serializers.BookModelSerializer(data=request_data)
if book_ser.is_valid():
book_obj = book_ser.save()
return APIResponse(results=serializers.BookModelsSerializer(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=Ture)
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)
八、单整体改、群整体改
def put(self, request, *args, **kwargs):
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，都需要通过数据，数据依旧给data，修改与新增不同点，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 isintance(request_data, list) or len(request_data) == 0:
return APIResponse(1, 'data error', http_status=400)
obj_list = []
data_list = []
for dic in request_data:
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)
九、单局部与群局部修改
def patch(self, request, *args, **kwargs):
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')
book_ser = serializers.BookModelSerializer(instance=book_obj, data=request_data, partial=Ture)
book_ser.is_valid(raise_exception=Ture)
book_obj = book_ser.save()
return APIResponse(results=serializers.BookModelSerializer(book_obj).data)
else: # 群增
if not isinstance(request_data, list) or len(request_data) == 0:
return APIResponse(1, 'data error', http_status=400)
# 注：一定不要在循环体中对循环对象进行增删(影响对象长度)的操作
obj_list = []
data_list = []
for dic in request_data:
# request_data可能是list，单内部不一定是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)