什么是序列化与反序列化
"""
序列化：对象转换为字符串用于传输
反序列化：字符串转换为对象用于使用
"""
drf序列化与反序列化
"""
序列化：Model类对象转换为字符串用于传输
反序列化：字符串转换为Model类对象用于使用
"""
Model类
创建数据库：终端
>: mysql -uroot -p密码
>: create database 数据库名 charset=utf8
配置数据库：settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': '数据库名',
'USER': 'root',
'PASSWORD': '密码'
}
}
修改操作数据库的模块：项目init文件
import pymysql
pymysql.install_as_MySQLdb()
创建model类：models.py
from django.db import models
class User(models.Model):
CHOICE_SEX = (
(0, '男'),
(1, '女')
)
name = models.CharField(max_length=32, verbose_name='姓名')
password = models.CharField(max_length=64, verbose_name='密码')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
class Meta:
# 自定义创建的表名
db_table = 'o_user'
# admin界面中显示的表面与表名复数形式
verbose_name = '用户'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
注册model类：admin.py
from django.contrib import admin
from api.models import User
admin.site.register(User)
数据库迁移：在项目目录下的终端
>: python3 manage.py makemigrations
>: python3 manage.py migrate
注册超级用户：在项目目录下的终端
>: python3 manage.py createsuperuser
登陆admin页面添加数据：浏览器
http://localhost:8000/admin/
路由分发
项目urls.py
from django.conf.urls import url, include
from django.contrib import admin
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^api/', include('api.urls'))
]
api应用urls.py
from django.conf.urls import url
urlpatterns = [
]
获取多资源 接口
序列化类：serializers.py
from rest_framework import serializers
# 为每一个Model类至少配一个Serializer类
class UserSerializer(serializers.Serializer):
# 序列化一个Model类对象，其实就是序列化该类的每一个属性
name = serializers.CharField()
password = serializers.CharField()
sex = serializers.IntegerField()
create_time = serializers.DateTimeField()
视图类：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个
class UsersAPIView(APIView):
def get(self, request, *args, **kwargs):
user_list = User.objects.all()
# instance存放的是queryset对象，many需要设置为True
user_data = UserSerializer(instance=user_list, many=True).data
return Response(
{
'status': 0,
'msg': 'ok',
'results': user_data
}
)
序列化字段操作（自定义字段）
序列化类修订：serializers.py
from rest_framework import serializers
# 为每一个Model类至少配一个Serializer类
class UserSerializer(serializers.Serializer):
# 序列化一个Model类对象，其实就是序列化该类的每一个属性
# 注意1：Model类与Serializer类是通过属性名建立关联的 - 属性名必须依照
name = serializers.CharField()
password = serializers.CharField()
# sex = serializers.IntegerField()
# 注意2：不需要通过给前台的数据，不需要提供该属性的序列化
# create_time = serializers.DateTimeField()
# 注意3：serializers.SerializerMethodField()可以产生自定义序列化属性(不需要和Model类属性同步)，
# 但要为其绑定一个提供值的函数，函数名为 get_属性(self, obj) (obj为参与序列化的Model类对象)
gender = serializers.SerializerMethodField()
def get_gender(self, obj):
# 该函数的返回值就作为对应自定义数据序列化后的值
return obj.get_sex_display()
新增单资源 接口
序列化类(反序列化类)：serializers.py
from rest_framework import serializers
from .models import User
class UserDeserializer(serializers.Serializer):
name = serializers.CharField(label='姓名', max_length=32, min_length=3, error_messages={
'max_length': '姓名太长',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密码', max_length=64, min_length=3, error_messages={
'max_length': '密码太长',
'min_length': '密码太短'
})
sex = serializers.IntegerField()
# required=False该字段前台可以不用传(不参与校验)
create_time = serializers.DateTimeField(required=False)
# 完成ORM的操作
# def save(self): # 不能直接重写save，因为系统的save可以完成新增或修改
# # print(self.validated_data)
# User.objects.create(**self.validated_data)
# 为post接口提供新增Model类对象的功能
def create(self, validated_data):
# 返回值：Model类要新增的对象
return User.objects.create(**validated_data)
视图类：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个
class UsersAPIView(APIView):
# 新增一个资源
def post(self, request, *args, **kwargs):
user_deser = UserDeserializer(data=request.data)
# raise_exception值为True，当校验失败，直接返回校验失败的错误信息
# result = user_deser.is_valid(raise_exception=True)
result = user_deser.is_valid()
if result:
new_user_obj = user_deser.save()
return Response({
'status': 0,
'msg': 'success',
'result': UserSerializer(new_user_obj).data
})
else:
return Response({
'status': 1,
'msg': 'failed',
'results': user_deser.errors
})
更新单资源 接口
序列化类(反序列化类)：serializers.py
from rest_framework import serializers
from .models import User
class UserDeserializer(serializers.Serializer):
name = serializers.CharField(label='姓名', max_length=32, min_length=3, error_messages={
'max_length': '姓名太长',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密码', max_length=64, min_length=3, error_messages={
'max_length': '密码太长',
'min_length': '密码太短'
})
sex = serializers.IntegerField()
# required=False该字段前台可以不用传(不参与校验)
create_time = serializers.DateTimeField(required=False)
# 完成ORM的操作
# def save(self): # 不能直接重写save，因为系统的save可以完成新增或修改
# # print(self.validated_data)
# User.objects.create(**self.validated_data)
# 为post接口提供新增Model类对象的功能
def create(self, validated_data):
# 返回值：Model类要新增的对象
return User.objects.create(**validated_data)
# 为put接口提供更新Model类对象的功能
def update(self, instance, validated_data):
# 操作model对象
# instance.name = validated_data.get('name')
# instance.password = validated_data.get('password')
# instance.sex = validated_data.get('sex')
# instance.save()
# 操作queryset对象
instance.update(**validated_data)
return instance
视图类：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个
class UsersAPIView(APIView):
# 更新一个资源
def put(self, request, *args, **kwargs):
# 要更新的资源的主键
pk = kwargs.get('pk')
# 操作更新时可以选择操作 queryset对象 或 model对象
# 操作model对象
# old_user_obj = User.objects.get(pk=pk)
# user_deser = UserDeserializer(instance=old_user_obj, data=request.data)
# 操作queryset对象
old_user_query = User.objects.filter(pk=pk)
user_deser = UserDeserializer(instance=old_user_query, data=request.data)
# raise_exception值为True，当校验失败，直接返回校验失败的错误信息
# result = user_deser.is_valid(raise_exception=True)
result = user_deser.is_valid()
if result:
# new_user_obj = user_deser.save() # 操作model对象
new_user_query = user_deser.save() # 操作queryset对象
new_user_obj = new_user_query.first()
return Response({
'status': 0,
'msg': 'success',
'result': UserSerializer(new_user_obj).data
})
else:
return Response({
'status': 1,
'msg': 'failed',
'results': user_deser.errors
})
删除单资源 接口
重构Model新增字段：models.py
class User(models.Model):
CHOICE_SEX = (
(0, '男'),
(1, '女')
)
name = models.CharField(max_length=32, verbose_name='姓名')
password = models.CharField(max_length=64, verbose_name='密码')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
# 新增：数据删除不是从数据库删除记录，而是修改记录状态，标示为已删除即可
is_delete = models.BooleanField(default=False)
class Meta:
# 自定义创建的表名
db_table = 'o_user'
# admin界面中显示的表面与表名复数形式
verbose_name = '用户'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
数据库迁移：在项目目录下的终端
>: python3 manage.py makemigrations
>: python3 manage.py migrate
视图类接口：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个
class UsersAPIView(APIView):
# 删除一个资源
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
try:
delete_user_obj = User.objects.get(pk=pk, is_delete=False)
# 完成删除信息的更新
delete_user_obj.is_delete = True
delete_user_obj.save()
return Response()
except:
return Response({
'status': 1,
'msg': '数据删除失败'
})
获取单资源 接口
序列化类：serializers.py
from rest_framework import serializers
# 为每一个Model类至少配一个Serializer类
class UserSerializer(serializers.Serializer):
# 序列化一个Model类对象，其实就是序列化该类的每一个属性
name = serializers.CharField()
password = serializers.CharField()
sex = serializers.IntegerField()
create_time = serializers.DateTimeField()
视图类：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个
class UsersAPIView(APIView):
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk', None)
if not pk:
user_query = User.objects.filter(is_delete=False).all()
else:
user_query = User.objects.filter(is_delete=False, pk=pk)
# 如果只操作一个对象，many参数需要为False(默认值)
# user_obj = User.objects.filter(is_delete=False, pk=pk).first()
# user_data = UserSerializer(instance=user_obj, many=False).data
user_data = UserSerializer(instance=user_query, many=True).data
return Response(
{
'status': 0,
'msg': 'ok',
'results': user_data
}
)
序列化基础：重点内容
模型类：models.py
from django.db import models
# Create your models here.
class User(models.Model):
CHOICE_SEX = (
(0, '男'),
(1, '女')
)
name = models.CharField(max_length=32, verbose_name='姓名')
password = models.CharField(max_length=64, verbose_name='密码')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
# 数据删除不是从数据库删除记录，而是修改记录状态，标示为已删除即可
is_delete = models.BooleanField(default=False)
class Meta:
# 自定义创建的表名
db_table = 'o_user'
# admin界面中显示的表面与表名复数形式
verbose_name = '用户'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
序列化类：
from rest_framework import serializers
from .models import User
class UserSerializer(serializers.Serializer):
# 序列化和反序列化都可以使用
name = serializers.CharField(label='姓名', max_length=32, min_length=3, error_messages={
'max_length': '姓名太长',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密码', max_length=64, min_length=3, error_messages={
'max_length': '密码太长',
'min_length': '密码太短'
})
# 只有反序列化使用 - 用 write_only=True 标示只参与反序列化
sex = serializers.IntegerField(write_only=True)
# 只有序列化使用 - 自定义字段 - 用 read_only=True 标示只参与序列化
gender = serializers.SerializerMethodField(read_only=True)
def get_gender(self, obj):
return obj.get_sex_display()
# 序列化与反序列化都不使用 - 1）注释 | 2）required=False, write_only=True
create_time = serializers.DateTimeField(required=False, write_only=True)
# 为全局校验钩子新增校验字段
re_password = serializers.CharField(label='确认密码', max_length=64, min_length=3, write_only=True, error_messages={
'max_length': '确认密码太长',
'min_length': '确认密码太短'
})
# 反序列化两大方法重写 - 新增create | 更新update
# 为post接口提供新增Model类对象的功能
def create(self, validated_data):
# 返回值：Model类要新增的对象
return User.objects.create(**validated_data)
# 为put接口提供更新Model类对象的功能
def update(self, instance, validated_data):
instance.update(**validated_data)
# 返回更新后的instance
return instance
# 局部钩子
def validate_sex(self, value):
if value not in (0, 1):
raise serializers.ValidationError('未知性别')
return value
# 全局钩子
def validate(self, attrs):
re_password = attrs.pop('re_password')
password = attrs.get('password')
if re_password != password:
raise serializers.ValidationError('二次密码不一致')
return attrs
视图类：
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 对应路由：/users/ | /users/pk/
# 功能：get获取所有 | post新增一个 | put修改一个 | delete删除一个 | get获取一个
class UsersAPIView(APIView):
# 获取所有资源 | 单个资源
def get(self, request, *args, **kwargs):
# 单个资源的主键
pk = kwargs.get('pk', None)
if not pk:
user_query = User.objects.filter(is_delete=False).all()
else:
user_query = User.objects.filter(is_delete=False, pk=pk)
user_data = UserSerializer(instance=user_query, many=True).data
return Response(
{
'status': 0,
'msg': 'ok',
'results': user_data
}
)
# 新增一个资源
def post(self, request, *args, **kwargs):
user_deser = UserSerializer(data=request.data)
# raise_exception值为True，当校验失败，直接返回校验失败的错误信息
# result = user_deser.is_valid(raise_exception=True)
result = user_deser.is_valid()
if result:
new_user_obj = user_deser.save()
return Response({
'status': 0,
'msg': 'success',
'result': UserSerializer(new_user_obj).data
})
else:
return Response({
'status': 1,
'msg': 'failed',
'results': user_deser.errors
})
# 更新一个资源
def put(self, request, *args, **kwargs):
pk = kwargs.get('pk')
old_user_query = User.objects.filter(pk=pk, is_delete=False)
# 没有数据
if not old_user_query:
return Response({
'status': 1,
'msg': 'update failed',
})
user_deser = UserSerializer(instance=old_user_query, data=request.data)
result = user_deser.is_valid()
if result:
new_user_query = user_deser.save()
new_user_obj = new_user_query.first()
return Response({
'status': 0,
'msg': 'success',
'result': UserSerializer(new_user_obj).data
})
else:
return Response({
'status': 1,
'msg': 'failed',
'results': user_deser.errors
})
# 删除一个资源
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
try:
delete_user_obj = User.objects.get(pk=pk, is_delete=False)
# 完成删除信息的更新
delete_user_obj.is_delete = True
delete_user_obj.save()
return Response()
except:
return Response({
'status': 1,
'msg': '数据删除失败'
})