什么是序列化與反序列化
"""
序列化：對象轉換為字符串用於傳輸
反序列化：字符串轉換為對象用於使用
"""
drf序列化與反序列化
"""
序列化：Model類對象轉換為字符串用於傳輸
反序列化：字符串轉換為Model類對象用於使用
"""
Model類
創建數據庫：終端
>: mysql -uroot -p密碼
>: create database 數據庫名 charset=utf8
配置數據庫：settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': '數據庫名',
'USER': 'root',
'PASSWORD': '密碼'
}
}
修改操作數據庫的模塊：項目init文件
import pymysql
pymysql.install_as_MySQLdb()
創建model類：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='密碼')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
class Meta:
# 自定義創建的表名
db_table = 'o_user'
# admin界面中顯示的表面與表名復數形式
verbose_name = '用戶'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
注冊model類：admin.py
from django.contrib import admin
from api.models import User
admin.site.register(User)
數據庫遷移：在項目目錄下的終端
>: python3 manage.py makemigrations
>: python3 manage.py migrate
注冊超級用戶：在項目目錄下的終端
>: python3 manage.py createsuperuser
登陸admin頁面添加數據：瀏覽器
http://localhost:8000/admin/
路由分發
項目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應用urls.py
from django.conf.urls import url
urlpatterns = [
]
獲取多資源 接口
序列化類：serializers.py
from rest_framework import serializers
# 為每一個Model類至少配一個Serializer類
class UserSerializer(serializers.Serializer):
# 序列化一個Model類對象，其實就是序列化該類的每一個屬性
name = serializers.CharField()
password = serializers.CharField()
sex = serializers.IntegerField()
create_time = serializers.DateTimeField()
視圖類：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個
class UsersAPIView(APIView):
def get(self, request, *args, **kwargs):
user_list = User.objects.all()
# instance存放的是queryset對象，many需要設置為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（自定義字段）
序列化類修訂：serializers.py
from rest_framework import serializers
# 為每一個Model類至少配一個Serializer類
class UserSerializer(serializers.Serializer):
# 序列化一個Model類對象，其實就是序列化該類的每一個屬性
# 注意1：Model類與Serializer類是通過屬性名建立關聯的 - 屬性名必須依照
name = serializers.CharField()
password = serializers.CharField()
# sex = serializers.IntegerField()
# 注意2：不需要通過給前台的數據，不需要提供該屬性的序列化
# create_time = serializers.DateTimeField()
# 注意3：serializers.SerializerMethodField()可以產生自定義序列化屬性(不需要和Model類屬性同步)，
# 但要為其綁定一個提供值的函數，函數名為 get_屬性(self, obj) (obj為參與序列化的Model類對象)
gender = serializers.SerializerMethodField()
def get_gender(self, obj):
# 該函數的返回值就作為對應自定義數據序列化后的值
return obj.get_sex_display()
新增單資源 接口
序列化類(反序列化類)：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': '姓名太長',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密碼', max_length=64, min_length=3, error_messages={
'max_length': '密碼太長',
'min_length': '密碼太短'
})
sex = serializers.IntegerField()
# required=False該字段前台可以不用傳(不參與校驗)
create_time = serializers.DateTimeField(required=False)
# 完成ORM的操作
# def save(self): # 不能直接重寫save，因為系統的save可以完成新增或修改
# # print(self.validated_data)
# User.objects.create(**self.validated_data)
# 為post接口提供新增Model類對象的功能
def create(self, validated_data):
# 返回值：Model類要新增的對象
return User.objects.create(**validated_data)
視圖類：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個
class UsersAPIView(APIView):
# 新增一個資源
def post(self, request, *args, **kwargs):
user_deser = UserDeserializer(data=request.data)
# raise_exception值為True，當校驗失敗，直接返回校驗失敗的錯誤信息
# 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
})
更新單資源 接口
序列化類(反序列化類)：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': '姓名太長',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密碼', max_length=64, min_length=3, error_messages={
'max_length': '密碼太長',
'min_length': '密碼太短'
})
sex = serializers.IntegerField()
# required=False該字段前台可以不用傳(不參與校驗)
create_time = serializers.DateTimeField(required=False)
# 完成ORM的操作
# def save(self): # 不能直接重寫save，因為系統的save可以完成新增或修改
# # print(self.validated_data)
# User.objects.create(**self.validated_data)
# 為post接口提供新增Model類對象的功能
def create(self, validated_data):
# 返回值：Model類要新增的對象
return User.objects.create(**validated_data)
# 為put接口提供更新Model類對象的功能
def update(self, instance, validated_data):
# 操作model對象
# instance.name = validated_data.get('name')
# instance.password = validated_data.get('password')
# instance.sex = validated_data.get('sex')
# instance.save()
# 操作queryset對象
instance.update(**validated_data)
return instance
視圖類：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個
class UsersAPIView(APIView):
# 更新一個資源
def put(self, request, *args, **kwargs):
# 要更新的資源的主鍵
pk = kwargs.get('pk')
# 操作更新時可以選擇操作 queryset對象 或 model對象
# 操作model對象
# old_user_obj = User.objects.get(pk=pk)
# user_deser = UserDeserializer(instance=old_user_obj, data=request.data)
# 操作queryset對象
old_user_query = User.objects.filter(pk=pk)
user_deser = UserDeserializer(instance=old_user_query, data=request.data)
# raise_exception值為True，當校驗失敗，直接返回校驗失敗的錯誤信息
# result = user_deser.is_valid(raise_exception=True)
result = user_deser.is_valid()
if result:
# new_user_obj = user_deser.save() # 操作model對象
new_user_query = user_deser.save() # 操作queryset對象
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
})
刪除單資源 接口
重構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='密碼')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
# 新增：數據刪除不是從數據庫刪除記錄，而是修改記錄狀態，標示為已刪除即可
is_delete = models.BooleanField(default=False)
class Meta:
# 自定義創建的表名
db_table = 'o_user'
# admin界面中顯示的表面與表名復數形式
verbose_name = '用戶'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
數據庫遷移：在項目目錄下的終端
>: python3 manage.py makemigrations
>: python3 manage.py migrate
視圖類接口：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個
class UsersAPIView(APIView):
# 刪除一個資源
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
try:
delete_user_obj = User.objects.get(pk=pk, is_delete=False)
# 完成刪除信息的更新
delete_user_obj.is_delete = True
delete_user_obj.save()
return Response()
except:
return Response({
'status': 1,
'msg': '數據刪除失敗'
})
獲取單資源 接口
序列化類：serializers.py
from rest_framework import serializers
# 為每一個Model類至少配一個Serializer類
class UserSerializer(serializers.Serializer):
# 序列化一個Model類對象，其實就是序列化該類的每一個屬性
name = serializers.CharField()
password = serializers.CharField()
sex = serializers.IntegerField()
create_time = serializers.DateTimeField()
視圖類：views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個
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)
# 如果只操作一個對象，many參數需要為False(默認值)
# 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
}
)
序列化基礎：重點內容
模型類：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='密碼')
sex = models.SmallIntegerField(choices=CHOICE_SEX, default=0)
create_time = models.DateTimeField(auto_now_add=True, blank=True)
# 數據刪除不是從數據庫刪除記錄，而是修改記錄狀態，標示為已刪除即可
is_delete = models.BooleanField(default=False)
class Meta:
# 自定義創建的表名
db_table = 'o_user'
# admin界面中顯示的表面與表名復數形式
verbose_name = '用戶'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
序列化類：
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': '姓名太長',
'min_length': '姓名太短'
})
password = serializers.CharField(label='密碼', max_length=64, min_length=3, error_messages={
'max_length': '密碼太長',
'min_length': '密碼太短'
})
# 只有反序列化使用 - 用 write_only=True 標示只參與反序列化
sex = serializers.IntegerField(write_only=True)
# 只有序列化使用 - 自定義字段 - 用 read_only=True 標示只參與序列化
gender = serializers.SerializerMethodField(read_only=True)
def get_gender(self, obj):
return obj.get_sex_display()
# 序列化與反序列化都不使用 - 1）注釋 | 2）required=False, write_only=True
create_time = serializers.DateTimeField(required=False, write_only=True)
# 為全局校驗鈎子新增校驗字段
re_password = serializers.CharField(label='確認密碼', max_length=64, min_length=3, write_only=True, error_messages={
'max_length': '確認密碼太長',
'min_length': '確認密碼太短'
})
# 反序列化兩大方法重寫 - 新增create | 更新update
# 為post接口提供新增Model類對象的功能
def create(self, validated_data):
# 返回值：Model類要新增的對象
return User.objects.create(**validated_data)
# 為put接口提供更新Model類對象的功能
def update(self, instance, validated_data):
instance.update(**validated_data)
# 返回更新后的instance
return instance
# 局部鈎子
def validate_sex(self, value):
if value not in (0, 1):
raise serializers.ValidationError('未知性別')
return value
# 全局鈎子
def validate(self, attrs):
re_password = attrs.pop('re_password')
password = attrs.get('password')
if re_password != password:
raise serializers.ValidationError('二次密碼不一致')
return attrs
視圖類：
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import User
from .serializers import UserSerializer
# 對應路由：/users/ | /users/pk/
# 功能：get獲取所有 | post新增一個 | put修改一個 | delete刪除一個 | get獲取一個
class UsersAPIView(APIView):
# 獲取所有資源 | 單個資源
def get(self, request, *args, **kwargs):
# 單個資源的主鍵
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
}
)
# 新增一個資源
def post(self, request, *args, **kwargs):
user_deser = UserSerializer(data=request.data)
# raise_exception值為True，當校驗失敗，直接返回校驗失敗的錯誤信息
# 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
})
# 更新一個資源
def put(self, request, *args, **kwargs):
pk = kwargs.get('pk')
old_user_query = User.objects.filter(pk=pk, is_delete=False)
# 沒有數據
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
})
# 刪除一個資源
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
try:
delete_user_obj = User.objects.get(pk=pk, is_delete=False)
# 完成刪除信息的更新
delete_user_obj.is_delete = True
delete_user_obj.save()
return Response()
except:
return Response({
'status': 1,
'msg': '數據刪除失敗'
})
