序列化组件的使用、反序列化、全局钩子和局部钩子的使用、raise_exception参数、modelserializer进行数据保存时的问题
序列化组件的使用
1. 在应用中创建一个py文件，比如叫做serializers.py
from rest_framework import serializers
class StudentSerizlizer(serializers.Serializer):
name = serializers.CharField()
age = serializers.IntegerField()
class_null = serializers.CharField()
description = serializers.CharField()
2. 在视图中使用
from django.shortcuts import render,HttpResponse
from django.http import JsonResponse
from students import models
# Create your views here.
from django.views import View
from .serializers import StudentSerizlizer
class StudentView(View):
def get(self,request):
# all = models.Student.objects.all() #quseryset model
one = models.Student.objects.get(id=1) #quseryset model
# serializer = StudentSerizlizer(all,many=True)
# serializer = StudentSerizlizer(all) #结果为：[{},{}]形式
serializer = StudentSerizlizer(one) #得到的结果为字典 data
print(serializer.data) #{'name': 'chao', 'age': 18, 'class_null': '31', 'description': 'xxxxx'}
return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
3. 应用配置文件
INSTALLED_APPS = [
...
'students.apps.StudentsConfig',
'rest_framework',
'ser'
]
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'drf01',
'HOST':'127.0.0.1',
'PORT':3306,
'USER':'root',
'PASSWORD':'123456'
}
}
反序列化功能
1. 创建反序列化组件
在应用中创建一个py文件，比如叫做serializers.py
from rest_framework import serializers
# 自定义校验函数
def check666(val):
if '666' in val:
raise serializers.ValidationError('不能光喊6666啊，没有用')
else:
return val
class StudentSerizlizer(serializers.Serializer):
name = serializers.CharField(max_length=4,validators=[check666,])
age = serializers.IntegerField(max_value=18)
class_null = serializers.CharField()
# description = serializers.CharField(required=False,allow_null=True)
# required=False,allow_null=True允许字段为空，也就是不用传递过来这个data
description = serializers.CharField(allow_blank=True)
#allow_blank=True 允许只为空字符串
2. 视图中使用
class Student(View):
def get..
...
def post(self,request):
# content-type
# if content-type == 'urlencoded':
# #username=chao&password=123&a=1
# request.POST['username'] = 'chao'
# elif content-type == 'form-data':
# # 分片接受数据
# request.FILES
# django没有自带解析json数据的解析器，所以需要我们手动的解析，但是drf中已经有了
# content - type == 'application/json'
#
print(request.POST)
data = {
'name':request.POST.get('name'),
'age':request.POST.get('age'),
'class_null':request.POST.get('class_null'),
'description':request.POST.get('description'),
}
ser = StudentSerizlizer(data=data)
print(ser.is_valid()) #校验，全部通过得到True，一个字段错了都是得到False
print(ser.errors) #所有字段的错误信息
# print(request.body)
return HttpResponse('ok')
全局钩子和局部钩子的使用
class StudentSerizlizer(serializers.Serializer):
# <QueryDict: {'name': ['c777'], 'age': ['6'], 'description': ['123'], 'class_null': ['1']}>
name = serializers.CharField(max_length=4,validators=[check666,])
age = serializers.IntegerField(max_value=18)
class_null = serializers.CharField()
# description = serializers.CharField(required=False,allow_null=True)
# required=False,allow_null=True允许字段为空，也就是不用传递过来这个data
description = serializers.CharField(allow_blank=True)
#allow_blank=True 允许只为空字符串
# 局部钩子：针对单个属性对应的数据进行校验
def validate_name(self,val):
# print('xxxxx>>>',val) #xxxxx>>> ccbb
if '777' in val:
raise serializers.ValidationError('不能有777')
return val #如果没有错误，需要return这个属性数据
# 全局钩子： 主要是针对多个属性数据进行校验
def validate(self,data):
print(data) #OrderedDict([('name', 'c778'), ('age', 6), ('class_null', '1'), ('description', '123')])
age = data.get('age')
class_null = data.get('age')
if age == class_null:
raise serializers.ValidationError('age和class——null不能相等')
return data #如果没有错误，全局钩子要return所有数据
视图部分
def post(self,request):
#
print(request.POST)
data = {
'name':request.POST.get('name'),
'age':request.POST.get('age'),
'class_null':request.POST.get('class_null'),
'description':request.POST.get('description'),
}
ser = StudentSerizlizer(data=data)
if ser.is_valid():
print(request.body)
ret = models.Student.objects.create(
**ser.validated_data
)
serializer = StudentSerizlizer(instance=ret)
print(serializer.data) #得到的是教研成功之后的所有正确数据
return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
# return JsonResponse({'xx':'xx'})
else:
return JsonResponse({'error':'有字段错误'})
执行顺序如下
# is_valid()方法时，先校验序列化器类中的所有属性Field(CharField(参数))参数对应的校验规则 # 再执行局部钩子 # 举例：比如有name和age两个属性，先执行name 的参数校验,在执行name的局部钩子(validate_name(self,val)),然后再执行age属性的参数校验,再执行age的局部钩子,最后所有属性的参数校验和局部钩子校验完成之后,执行全局钩子 # 最后执行全局钩子
常用字段和参数
| 字段 | 字段构造方式 |
|---|---|
| BooleanField | BooleanField() |
| NullBooleanField | NullBooleanField() |
| CharField | CharField(max_length=None, min_length=None, allow_blank=False, trim_whitespace=True) |
| EmailField | EmailField(max_length=None, min_length=None, allow_blank=False) |
| RegexField | RegexField(regex, max_length=None, min_length=None, allow_blank=False) |
| SlugField | SlugField(maxlength=50, min_length=None, allow_blank=False) 正则字段，验证正则模式 [a-zA-Z0-9-]+ |
| URLField | URLField(max_length=200, min_length=None, allow_blank=False) |
| UUIDField | UUIDField(format='hex_verbose') format: 1) 'hex_verbose' 如"5ce0e9a5-5ffa-654b-cee0-1238041fb31a" 2） 'hex' 如 "5ce0e9a55ffa654bcee01238041fb31a" 3）'int' - 如: "123456789012312313134124512351145145114" 4）'urn' 如: "urn:uuid:5ce0e9a5-5ffa-654b-cee0-1238041fb31a" 微软时间戳，通过微秒生成一个随机字符串 |
| IPAddressField | IPAddressField(protocol='both', unpack_ipv4=False, **options) |
| IntegerField | IntegerField(max_value=None, min_value=None) |
| FloatField | FloatField(max_value=None, min_value=None) |
| DecimalField | DecimalField(max_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None) max_digits: 最多位数 decimal_palces: 小数点位置 |
| DateTimeField | DateTimeField(format=api_settings.DATETIME_FORMAT, input_formats=None) |
| DateField | DateField(format=api_settings.DATE_FORMAT, input_formats=None) |
| TimeField | TimeField(format=api_settings.TIME_FORMAT, input_formats=None) |
| DurationField | DurationField() |
| ChoiceField | ChoiceField(choices) choices与Django的用法相同 |
| MultipleChoiceField | MultipleChoiceField(choices) |
| FileField | FileField(max_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URL) |
| ImageField | ImageField(max_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URL) |
| ListField | ListField(child=, min_length=None, max_length=None) |
| DictField | DictField(child=) |
选项参数：
| 参数名称 | 作用 |
|---|---|
| max_length | 最大长度 |
| min_length | 最小长度 |
| allow_blank | 是否允许为空 |
| trim_whitespace | 是否截断空白字符 |
| max_value | 最大值 |
| min_value | 最小值 |
通用参数：
| 参数名称 | 说明 |
|---|---|
| read_only | 表明该字段仅用于序列化输出，默认False |
| write_only | 表明该字段仅用于反序列化输入，默认False |
| required | 表明该字段在反序列化时必须输入，默认True |
| default | 反序列化时使用的默认值 |
| allow_null | 表明该字段是否允许传入None，默认False |
| validators | 该字段使用的验证器 |
| error_messages | 包含错误编号与错误信息的字典 |
| label | 用于HTML展示API页面时，显示的字段名称 |
| help_text | 用于HTML展示API页面时，显示的字段帮助提示信息 |
raise_exception参数
等于True会主动抛出异常
serializer.is_valid(raise_exception=True)
保存数据
方式1 直接在视图中保存
if ser.is_valid():
# print(request.body)
ret = models.Student.objects.create(
**ser.validated_data
)
serializer = StudentSerizlizer(instance=ret)
return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
else:
print(ser.errors)
return JsonResponse({'error':'有字段错误'})
方式2
在序列化器中定义create方法来数据的保存
class StudentSerizlizer(serializers.Serializer):
# <QueryDict: {'name': ['c777'], 'age': ['6'], 'description': ['123'], 'class_null': ['1']}>
name = serializers.CharField(max_length=4,validators=[check666,])
...
def create(self, validated_data):
# self.validated_data
# validated_data
# print('>>',self.validated_data)
print('>>',validated_data)
ret = models.Student.objects.create(
**validated_data
)
return ret
视图中通过save方法来触发,序列化器类中的create方法
if ser.is_valid():
instance = ser.save() #得到create方法的返回值
serializer = StudentSerizlizer(instance=instance)
return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
# return JsonResponse({'xx':'xx'})
更新数据
在序列化器中定义update方法来数据的更新
class StudentSerizlizer(serializers.Serializer):
# <QueryDict: {'name': ['c777'], 'age': ['6'], 'description': ['123'], 'class_null': ['1']}>
name = serializers.CharField(max_length=4,validators=[check666,])
...
# 做更新动作
def update(self, instance, validated_data):
# print(instance)
# print(validated_data)
instance.name = validated_data['name']
instance.age = validated_data['age']
instance.class_null = validated_data['class_null']
instance.description = validated_data['description']
instance.save()
return instance
视图
def put(self,request):
data = {
'id': 2,
'name':'xx',
'age':8,
'sex':0,
'class_null':'9',
'description':'xx',
}
obj = models.Student.objects.get(id=data.get('id'))
s_obj = StudentSerizlizer(instance=obj,data=data) # 实例化序列化器类时,传入instance参数
if s_obj.is_valid():
s_obj.save() #触发序列化器类的update方法
else:
return JsonResponse({'error':'数据错误'})
read_only和write_only参数的区别
from rest_framework import serializers
class StudentSerizlizer(serializers.Serializer):
id = serializers.IntegerField(read_only=True)
# read_only=True，序列化时序列化出该字段数据，反序列化校验时不要校验这个数据
name = serializers.CharField(max_length=4,)
age = serializers.IntegerField(max_value=18,write_only=True)
# write_only=True，序列化时不序列化这个字段数据，反序列校验时，需要客户端传递这个数据过来进行校验
class_null = serializers.CharField()
description = serializers.CharField(allow_blank=True)
视图部分
from django.shortcuts import render
from django.views import View
# Create your views here.
from students import models
from .serializers import StudentSerizlizer
from django.http import JsonResponse
class StudentView(View):
def get(self,request):
all = models.Student.objects.all()
serializer = StudentSerizlizer(instance=all, many=True)
return JsonResponse(serializer.data, safe=False, json_dumps_params={'ensure_ascii':False})
def post(self,request):
print(request.POST)
data = {
'name':request.POST.get('name'),
'sex':request.POST.get('sex'),
'age':request.POST.get('age'),
'class_null':request.POST.get('class_null'),
'description':request.POST.get('description'),
}
serializer = StudentSerizlizer(data=data)
serializer.is_valid()
print(serializer.errors)
print('正确数据：',serializer.validated_data)
return JsonResponse({'xx':'xx'})
partial参数：默认为False
def put(self,request):
data = {
'name':'chao',
'age':18
}
serializer = StudentSerizlizer(data=data,partial=True)
# partial=True:只需要校验传入给序列化器的数据，适用于部分数据更新
serializer.is_valid()
print(serializer.errors)
print('正确数据：', serializer.validated_data)
return JsonResponse({'ss': 'kk'})
modelSerializer的使用
序列化和反序列化的使用
定义如下的类
from rest_framework import serializers
from students import models
class StudentModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Student
fields = '__all__'
# fields = ['id', 'name', 'age']
# fields = ['id', 'name', 'age']
# exclude = ['name','age']
extra_kwargs = {
'id':{'read_only':True,},
'age':{'write_only':True,}
}
'''
id
name = models.CharField(max_length=100,verbose_name="姓名",help_text='提示文本：不能为空')
sex = models.BooleanField(default=1,verbose_name="性别")
age = models.IntegerField(verbose_name="年龄")
class_null = models.CharField(max_length=5,verbose_name="班级编号")
description = models.TextField(max_length=1000,verbose_name="个性签名")
'''
'''
id = serializers.IntegerField(read_only=True)
name = serializers.CharField(max_length=6,) # name char(6)
age = serializers.IntegerField(max_value=18,write_only=True)
sex = serializers.BooleanField()
class_null = serializers.CharField()
description = serializers.CharField(allow_blank=True)
'''
视图当中使用
from django.shortcuts import render
from django.http import JsonResponse
# Create your views here.
from django.views import View
from .serializers import StudentModelSerializer
from students import models
class StudentView(View):
def get(self,request):
all = models.Student.objects.all()
model_ser = StudentModelSerializer(instance=all,many=True)
print()
return JsonResponse(model_ser.data, safe=False, json_dumps_params={'ensure_ascii':False})
def post(self,request):
print(request.POST)
obj = StudentModelSerializer(data=request.POST)
if obj.is_valid():
print(obj.validated_data)
obj.save() #自动能够帮我们进行数据保存
return JsonResponse({'msg':'success'})
print(obj.errors)
print(obj.validated_data)
return JsonResponse({'xx':'ssssss'})
modelserializer进行数据保存时的问题
视图相关
APIView类
request对象
from rest_framework.views import APIView
class UserView(APIView):
def get(self,request):
print(request.GET)
print(request.query_params)
# request.GET和request.query_params是等价的
return JsonResponse({'xx':'xxxxx'})
def post(self,request):
print(request)
# 当发送的数据格式为..urlencoded类型时,request.POST和request.data等价
# print(request.POST.getlist('hobby')) #<QueryDict: {'name': ['小林2'], 'age': ['6']}>
# 当发送过来的是json类型数据时,我们使用request.data属性能够获取到数据
print(request.data) #{'username': 'xxxx', 'password': '123'},普通字典类型
# request.data能够获取到客户端发送过来的json类型数据，但是得到的结果为普通字典类型，但是如果是多选数据，不能使用getlist方法获取
return JsonResponse({'xx': 'xxxxx'})
response对象
查看drf的默认配置
from rest_framework import settings
引入response
from rest_framework.response import Response
Response默认响应的是json数据类型
当用浏览器访问时看到页面效果.
用户配置替换drf内部配置的写法
REST_FRAMEWORK = {
'DEFAULT_RENDERER_CLASSES': ( # 默认响应渲染类
'rest_framework.renderers.JSONRenderer', # json渲染器
'rest_framework.renderers.BrowsableAPIRenderer', # 浏览器API渲染器
)
}
response的方法的相关参数
Response(data, status=None, template_name=None, headers=None, content_type=None)
’响应状态码
from rest_framework import status
# return Response({'xx':'xxxxx'}, status=201)
return Response({'xx':'xxxxx'}, status=status.HTTP_201_CREATED)
所有状态码
HTTP_100_CONTINUE = 100 HTTP_101_SWITCHING_PROTOCOLS = 101 HTTP_200_OK = 200 HTTP_201_CREATED = 201 HTTP_202_ACCEPTED = 202 HTTP_203_NON_AUTHORITATIVE_INFORMATION = 203 HTTP_204_NO_CONTENT = 204 HTTP_205_RESET_CONTENT = 205 HTTP_206_PARTIAL_CONTENT = 206 HTTP_207_MULTI_STATUS = 207 HTTP_208_ALREADY_REPORTED = 208 HTTP_226_IM_USED = 226 HTTP_300_MULTIPLE_CHOICES = 300 HTTP_301_MOVED_PERMANENTLY = 301 HTTP_302_FOUND = 302 HTTP_303_SEE_OTHER = 303 HTTP_304_NOT_MODIFIED = 304 HTTP_305_USE_PROXY = 305 HTTP_306_RESERVED = 306 HTTP_307_TEMPORARY_REDIRECT = 307 HTTP_308_PERMANENT_REDIRECT = 308 HTTP_400_BAD_REQUEST = 400 HTTP_401_UNAUTHORIZED = 401 HTTP_402_PAYMENT_REQUIRED = 402 HTTP_403_FORBIDDEN = 403 HTTP_404_NOT_FOUND = 404 HTTP_405_METHOD_NOT_ALLOWED = 405 HTTP_406_NOT_ACCEPTABLE = 406 HTTP_407_PROXY_AUTHENTICATION_REQUIRED = 407 HTTP_408_REQUEST_TIMEOUT = 408 HTTP_409_CONFLICT = 409 HTTP_410_GONE = 410 HTTP_411_LENGTH_REQUIRED = 411 HTTP_412_PRECONDITION_FAILED = 412 HTTP_413_REQUEST_ENTITY_TOO_LARGE = 413 HTTP_414_REQUEST_URI_TOO_LONG = 414 HTTP_415_UNSUPPORTED_MEDIA_TYPE = 415 HTTP_416_REQUESTED_RANGE_NOT_SATISFIABLE = 416 HTTP_417_EXPECTATION_FAILED = 417 HTTP_418_IM_A_TEAPOT = 418 HTTP_422_UNPROCESSABLE_ENTITY = 422 HTTP_423_LOCKED = 423 HTTP_424_FAILED_DEPENDENCY = 424 HTTP_426_UPGRADE_REQUIRED = 426 HTTP_428_PRECONDITION_REQUIRED = 428 HTTP_429_TOO_MANY_REQUESTS = 429 HTTP_431_REQUEST_HEADER_FIELDS_TOO_LARGE = 431 HTTP_451_UNAVAILABLE_FOR_LEGAL_REASONS = 451 HTTP_500_INTERNAL_SERVER_ERROR = 500 HTTP_501_NOT_IMPLEMENTED = 501 HTTP_502_BAD_GATEWAY = 502 HTTP_503_SERVICE_UNAVAILABLE = 503 HTTP_504_GATEWAY_TIMEOUT = 504 HTTP_505_HTTP_VERSION_NOT_SUPPORTED = 505 HTTP_506_VARIANT_ALSO_NEGOTIATES = 506 HTTP_507_INSUFFICIENT_STORAGE = 507 HTTP_508_LOOP_DETECTED = 508 HTTP_509_BANDWIDTH_LIMIT_EXCEEDED = 509 HTTP_510_NOT_EXTENDED = 510 HTTP_511_NETWORK_AUTHENTICATION_REQUIRED = 511
headers定制响应头键值对
return Response({'xx':'xxxxx'}, status=status.HTTP_201_CREATED,headers={'xx':'oo'})
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