pip install djangorestframework

INSTALLED_APPS = [
    ...
    'rest_framework',
]

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        fields = '__all__'

from rest_framework.viewsets import ModelViewSet
from .serializers import BookInfoSerializer
from .models import BookInfo
?
class BookInfoViewSet(ModelViewSet):
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoSerializer

from . import views
from rest_framework.routers import DefaultRouter
?
urlpatterns = [
    ...
]
?
router = DefaultRouter()  # 可以处理视图的路由器
router.register(r'books', views.BookInfoViewSet)  # 向路由器中注册视图集
?
urlpatterns += router.urls  # 将路由器中的所以路由信息追到到django的路由列表中

python manage.py runserver

1. 序列化,序列化器会把模型对象转换成字典, 经过response以后变成json字符串
2. 完成数据校验功能
3. 反序列化,把客户端发送过来的数据, 经过request以后变成字典,序列化器可以把字典转成模型

class BookInfo(models.Model):
    btitle = models.CharField(max_length=20, verbose_name='名称')
    bpub_date = models.DateField(verbose_name='发布日期', null=True)
    bread = models.IntegerField(default=0, verbose_name='阅读量')
    bcomment = models.IntegerField(default=0, verbose_name='评论量')
    image = models.ImageField(upload_to='booktest', verbose_name='图片', null=True)

from rest_framework import serializers
class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    id = serializers.IntegerField(label='ID', read_only=True)
    btitle = serializers.CharField(label='名称', max_length=20)
    bpub_date = serializers.DateField(label='发布日期', required=False)
    bread = serializers.IntegerField(label='阅读量', required=False)
    bcomment = serializers.IntegerField(label='评论量', required=False)
    image = serializers.ImageField(label='图片', required=False)

Serializer(instance=None, data=empty, **kwarg)

serializer = AccountSerializer(account, context={'request': request})

from django.http import JsonResponse
from django.views import View
from booktest.models import BookInfo
#导入序列化器类
from .serializers import BookInfoSeriallzer
?
class BookInfoView(View):
    def get(self,request):
        books = BookInfo.objects.all()
        serializer = BookInfoSeriallzer(instance=books,many=True)
        print(serializer.data)
        return JsonResponse(serializer.data,safe=False)

from django.views import View
from django.http import JsonResponse
from django.http import QueryDict
from .serializers import BookInfo2Serializer
class BookInfo2View(View):
    def post(self,request):
        """添加一本图书"""
        # 接受数据
        data = request.POST
        # 反序列化
        serializer = BookInfo2Serializer(data=data)
        # 1. 验证数据
        # raise_exception=True 把验证的错误信息返回给客户端,同时阻止程序继续往下执行
        serializer.is_valid(raise_exception=True)
        # is_valid调用验证方式: 字段选项validators->自定义验证方法[单字段]->自定义验证方法[多字段]
        # 验证成功后的数据
        # print(serializer.validated_data)
        # 2. 转换数据成模型,同步到数据库中
        result = serializer.save() # save会自动调用序列化器类里面声明的create/update方法，返回值是当前新增/更新的模型对象
?
        # 响应数据
        return JsonResponse(serializer.data)

class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...
?
    def validate_btitle(self, value):
        if 'django' not in value.lower():
            raise serializers.ValidationError("图书不是关于Django的")
        return value

class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...
?
    def validate(self, attrs):
        bread = attrs['bread']
        bcomment = attrs['bcomment']
        if bread < bcomment:
            raise serializers.ValidationError('阅读量小于评论量')
        return attrs

def about_django(value):
    if 'django' not in value.lower():
        raise serializers.ValidationError("图书不是关于Django的")
?
class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    id = serializers.IntegerField(label='ID', read_only=True)
    btitle = serializers.CharField(label='名称', max_length=20, validators=[about_django])
    bpub_date = serializers.DateField(label='发布日期', required=False)
    bread = serializers.IntegerField(label='阅读量', required=False)
    bcomment = serializers.IntegerField(label='评论量', required=False)
    image = serializers.ImageField(label='图片', required=False)

class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...
?
    def create(self, validated_data):
        """新建"""
        return BookInfo(**validated_data)
?
    def update(self, instance, validated_data):
        """更新，instance为要更新的对象实例"""
        instance.btitle = validated_data.get('btitle', instance.btitle)
        instance.bpub_date = validated_data.get('bpub_date', instance.bpub_date)
        instance.bread = validated_data.get('bread', instance.bread)
        instance.bcomment = validated_data.get('bcomment', instance.bcomment)
        return instance

book = serializer.save()

# save之所以可以自动识别，什么时候执行create ，什么时候执行update
# 主要是看创建序列化器对象时，是否有传入instance参数，
# 有instance参数，则save会调用序列化器内部的update方法
# 没有instance参数，则save会调用序列化器内部的create方法

# request.user 是django中记录当前登录用户的模型对象
serializer.save(owner=request.user)

# Update `comment` with partial data
serializer = CommentSerializer(comment, data={'content': u'foo bar'}, partial=True)

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        fields = '__all__'

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        fields = ('id', 'btitle', 'bpub_date')

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        exclude = ('image',)

class HeroInfoSerializer(serializers.ModelSerializer):
    hbook = BookInfoSerializer()
?
    class Meta:
        model = HeroInfo
        fields = ('id', 'hname', 'hgender', 'hcomment', 'hbook')

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        fields = ('id', 'btitle', 'bpub_date'， 'bread', 'bcomment')
        read_only_fields = ('id', 'bread', 'bcomment')

class BookInfoSerializer(serializers.ModelSerializer):
    """图书数据序列化器"""
    class Meta:
        model = BookInfo
        fields = ('id', 'btitle', 'bpub_date', 'bread', 'bcomment')
        extra_kwargs = {
            'bread': {'min_value': 0, 'required': True},
            'bcomment': {'min_value': 0, 'required': True},
        }
?
# BookInfoSerializer():
#    id = IntegerField(label='ID', read_only=True)
#    btitle = CharField(label='名称', max_length=20)
#    bpub_date = DateField(allow_null=True, label='发布日期', required=False)
#    bread = IntegerField(label='阅读量', max_value=2147483647, min_value=0, required=True)
#    bcomment = IntegerField(label='评论量', max_value=2147483647, min_value=0, required=True)