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  • DRF框架之Serializer序列化器的序列化和反序列化操作

    DRF 序列化 和 反序列化

    转载自:https://blog.csdn.net/qq_42517220/article/details/94441021

    序列化

    定义

    序列化:将model模型对象转换为json格式的字符串,我们可以对返回的数据进行过滤(一般是后端构造数据,返回给前端)

    继承说明:Django REST framework中的Serializer使用类来定义,须继承自

    rest_framework.serializers.Serializer
    或
    rest_framework.serializers.ModelSerializer
    

    Serializers使用方式

    例如,我们已有了一个数据库模型类BookInfo

    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)
    

    我们想为这个模型类提供一个序列化器,在应用中models.py同级目录创建serializers.py文件,定义内容如下:

    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)
        logo = serializers.ImageField(label='图片', required=False)
    

    在试图views.py文件中使用如下:

    from django.views import View
    from .models import BookInfo
    from .serializers import BookInfoSerializer
    
    class BookView(View):
    	def get(self, request, pk):
    		book = BookInfo.objects.get(pk=pk)
    		# 构建序列化对象,将模型对象传入,将其转换为json格式字符串
    		# 转换后的格式:{"id": 1, ....}, 键为serializers序列化器中定义的所有字段
    		serializer = BookInfoSerializer(book)
    		# 转换后的字符串对象保存在serializer的data属性中
    		return JsonResponse(serializer.data)
    
    • serializer序列化器说明:

    • BookInfoSerializer:默认只能接收单个对象,如果想要接收一个queryset对象,并对其进行转换,需要设定参数:many=True

      from django.views import View
      from .models import BookInfo
      from .serializers import BookInfoSerializer
      
      class BookView(View):
      	def get(self, request):
      		books = BookInfo.objects.all()
      		# 构建序列化对象,将模型对象传入,将其转换为json格式字符串
      		serializer = BookInfoSerializer(books, many=True)
      		# 转换后的字符串对象保存在serializer的data属性中
      		# 转换后的格式:[{}, {}, ...], 内部字典数据同上,注意该数据并非json,仅仅是长得像json格式的字符串
      		return JsonResponse(serializer.data, safe=False)
      

      注意:JsonResponse转换列表时需要给定参数:safe=False,否则会报错

    序列化的高级使用

    1、关联对象的序列化

    PrimaryKeyRelatedField:返回关联对象的主键id

    # models.py
    
    from django.db import models
    
    class BookInfo(models.Model):
        btitle = models.CharField(max_length=128, verbose_name='书名')
        pbublic_date = models.DateField(verbose_name='发布日期')
        bread = models.IntegerField(default=0, verbose_name='阅读量')
        bcomment = models.IntegerField(default=0, verbose_name='评论量')
        is_delete = models.BooleanField(default=0, verbose_name='逻辑删除')
        logo = models.ImageField(upload_to='booktest', verbose_name='封面图', null=True)
        
        class Meta:
            db_table = 'tb_books'
            verbose_name = '图书'
            verbose_name_plural = verbose_name
    
        def __str__(self):
            return self.btitle
    
    class HeroInfo(models.Model):
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        hname = models.CharField(max_length=36, verbose_name='名字')
        hgender = models.SmallIntegerField(choices=GENDER_CHOICES, default=0, verbose_name='性别')
        hcomment = models.CharField(max_length=200, null=True, verbose_name='描述信息')
        hbook = models.ForeignKey(BookInfo, on_delete=models.CASCADE, verbose_name='图书')
        
        class Meta:
        db_table = 'tb_heros'
        verbose_name = '英雄'
        verbose_name_plural = verbose_name
    
        def __str__(self):
            return self.hname
    
    # serializer.py
    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = serializers.IntegerField(label='ID', read_only=True)
        hname = serializers.CharField(label='名字', max_length=20)
        hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        # 英雄关联到的书籍对象,此处必须指定关联到的对象queryset或者指定参数 read_only=True
        # hbook = serializers.PrimaryKeyRelatedField(queryset=BookInfo.objects.all())
        hbook = serializers.PrimaryKeyRelatedField(read_only=True)
    
    # views.py
    class HeroView(View):
        def get(self, request, pk):
            hero = HeroInfo.objects.get(pk=pk)
            seralizer = HeroInfoSerializer(hero)
            return JsonResponse(seralizer.data)
    
    # urls.py
    from django.urls import path
    from . import views
    
    urlpatterns = [
        path('heros/<hid>', views.HeroView.as_view()),
    ]
    
    # http://127.0.0.1:8000/heros/5
    
    {
    	id: 5,
    	hname: "贾宝玉",
    	hgender: 0,
    	hcomment: null,
    	hbook: 1
    }
    

    StringRelatedField:返回关联对象模型类中定义的__str__方法返回值

    serializers.py

    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = serializers.IntegerField(label='ID', read_only=True)
        hname = serializers.CharField(label='名字', max_length=20)
        hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        # 返回关联对象模型类中定义的__str__方法返回值
        # 为什么此处不需要指定read_only=True,因为此方法内部自己将其封装进去了
        """
        class StringRelatedField(RelatedField):
    	    def __init__(self, **kwargs):
    	        kwargs['read_only'] = True
    	        super(StringRelatedField, self).__init__(**kwargs)
       
       def to_representation(self, value):
            return six.text_type(value)
    	"""
    	hbook = serializers.StringRelatedField()
    
    {
    	id: 5,
    	hname: "贾宝玉",
    	hgender: 0,
    	hcomment: null,
    	hbook: "红楼梦"
    }
    
    

    SlugRelatedField:显示关联对象的某一个字段

    serializers.py

    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = serializers.IntegerField(label='ID', read_only=True)
        hname = serializers.CharField(label='名字', max_length=20)
        hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        # 显示关联对象pbublic_date字段值
    	hbook = serializers.SlugRelatedField(label='图书', read_only=True, slug_field='pbublic_date')
    
    {
    	id: 5,
    	hname: "贾宝玉",
    	hgender: 0,
    	hcomment: null,
    	hbook: "1971-07-01"
    }
    
    

    使用关联对象的序列化器

    serializers.py

    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = serializers.IntegerField(label='ID', read_only=True)
        hname = serializers.CharField(label='名字', max_length=20)
        hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        # 显示关联对象的序列化后的数据
        hbook = BookInfoSerializer()
    

    {
    id: 5,
    hname: "贾宝玉",
    hgender: 0,
    hcomment: null,
    hbook: {
    id: 1,
    btitle: "红楼梦",
    bread: 0,
    bcomment: 0,
    logo: null
    }
    }

    重写to_representation方法

    序列化器的每个字段实际都是由该字段类型的to_representation方法决定格式的,可以通过重写该方法来决定格式

    注意,to_representations方法不仅局限在控制关联对象格式上,适用于各个序列化器字段类型。

    自定义一个新的关联字段:

    # serializers.py
    
    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class BookRelateField(serializers.RelatedField):
        """自定义用于处理图书的字段"""
        def to_representation(self, value):
            return 'Book: %d %s' % (value.id, value.btitle)
    
    

    指明hbook为BookRelateField类型

    # serializer.py
    from rest_framework import serializers
    
    from books.models import BookInfo
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDE_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = serializers.IntegerField(label='ID', read_only=True)
        hname = serializers.CharField(label='名字', max_length=20)
        hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        # 显示我们上述自定义的类对象的返回值
    	hbook = BookRelateField(read_only=True)
    
    # 使用效果
    
    # http://127.0.0.1:8000/heros/5/
    
    {
    	id: 5,
    	hname: "贾宝玉",
    	hgender: 0,
    	hcomment: null,
    	hbook: "Book: 1 红楼梦"
    }
    

    反向序列化(即从一到多:序列化书籍中的英雄对象)

    # serializers.py
    
    from rest_framework import serializers
    
    from books.models import BookInfo
    
    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)
        is_delete = serializers.BooleanField(write_only=True)
        logo = serializers.ImageField(label='图片', required=False)
        # 使用关联对象的序列化器,将书本反向关联的英雄序列化输出
        # 注意 many=True,一定不能省略
        heroinfo_set = HeroInfoSerializer(many=True)
    
    {
    	id: 2,
    	btitle: "西游记",
    	bread: 0,
    	bcomment: 0,
    	logo: null,
    	heroinfo_set: [
    		{
    			id: 1,
    			hname: "孙悟空",
    			hgender: 0,
    			hcomment: null,
    			hbook: 2
    		},
    		{
    			id: 2,
    			hname: "猪八戒",
    			hgender: 0,
    			hcomment: null,
    			hbook: 2
    		},
    		{
    			id: 3,
    			hname: "沙悟净",
    			hgender: 0,
    			hcomment: null,
    			hbook: 2
    		},
    		{
    			id: 4,
    			hname: "唐僧",
    			hgender: 0,
    			hcomment: null,
    			hbook: 2
    		}
    	]
    }
    

    ModelSerializer(模型类序列化器)使用方式

    功能同我们上述定义的序列化器,但更简单方便

     from rest_framework import ModelSerializer
    
    from .models import BookInfo
    
    class BookInfoSerializer(serializers.ModelSerializer):
        """图书数据序列化器"""
        class Meta:
    
    		# 指要序列化的模型对象
    
       		model = BookInfo
    
    		# 列出要序列化的字段,格式为列表或元组, __all__代表序列化所有字段
    
       		fields = "__all__"
    

    使用fields来明确字段,__all__表名包含所有字段,也可以写明具体哪些字段,如

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

    使用exclude可以明确排除掉哪些字段,注意:exclude和fields不能同时存在

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

    默认ModelSerializer使用主键作为关联字段,但是我们可以使用depth来简单的生成嵌套表示,depth应该是整数,表明嵌套的层级数量。如:现在有一个英雄model,与上述model是多对一关系(即一本书中会有多个英雄)

    # models.py
    
    from books import models
    
    class HeroInfoSerializer(serializers.Serializer):
        """英雄数据序列化器"""
        GENDER_CHOICES = (
            (0, 'male'),
            (1, 'female')
        )
        id = models.IntegerField(label='ID', read_only=True)
        hname = models.CharField(label='名字', max_length=20)
        hgender = models.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
        hcomment = models.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
        book = models.ForeignKey(BookInfo, related_name='book')
        
        class Meta:
            db_table = 'tb_heros'
            verbose_name = '英雄'
            verbose_name_plural = verbose_name
    
        def __str__(self):
            return self.hname
    
    
    # serializers.py
    
    class HeroInfoSerializer(serializers.ModelSerializer):
        class Meta:
            model = HeroInfo
            fields = '__all__'
            depth = 1
    
    # views.py
    
    from booktest.serializers import HeroInfoSerializer
    from booktest.models import HeroInfo
    
    class HeroView(View):
    	def get(self, request, pk):
    		hero = HeroInfo.objects.get(id=6)
    		serializer = HeroInfoSerializer(hero)
    		print(serializer.data)
    
    # 打印结果
    {
    	'id': 6, 
    	'hname': '乔峰', 
    	'hgender': 1, 
    	'hcomment': '降龙十八掌', 
    	'hbook': {
    		'id': 2, 
    		'btitle': '天龙八部', 
    		'bpub_date': '1986-07-24', 
    		'bread': 36, 
    		'bcomment': 40, 
    		'logo': None
    	}
    }
    

    指明只读字段:可以通过read_only_fields指明只读字段,即仅用于序列化输出的字段,在反序列化时不允许修改

    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')
    
    

    指明只读字段:可以通过write_only_fields指明只写字段,即仅用于反序列化验证的字段,在序列化时不进行显示

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

    我们可以使用extra_kwargs参数为ModelSerializer添加或修改原有的选项参数
    比如在数据库声明时未指定字段的最大值与最小值,就可以通过该属性动态添加

    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': {'max_value': 0, 'required': True}},
            }
    

    反序列化

    定义:
    反序列化:将json格式的字符串转换为对象,我们可以对接收的数据进行校验(一般是后端接收前端传送的数据进行校验后进行数据库相关操作:增加、修改 serializer.save())

    继承说明:Django REST framework中的Serializer使用类来定义,须继承自

    rest_framework.serializers.Serializer
    或
    rest_framework.serializers.ModelSerializer
    

    说明:序列化和反序列化使用同一序列化器,通过指定不同参数来区别是用于序列化还是反序列化

    # 所有序列化器基类
    
    class BaseSerializer(Field):
    	def __init__(self, instance=None, data=empty, **kwargs):
        self.instance = instance
        if data is not empty:
            self.initial_data = data
        self.partial = kwargs.pop('partial', False)
        self._context = kwargs.pop('context', {})
        kwargs.pop('many', None)
        super(BaseSerializer, self).__init__(**kwargs)
    

    当我们只传递一个参数时,且没有指明传递对象,按位置传参,则将book对象传递给instance,此时默认为进行序列化输出

    # views.py
    
    class BooksView(View):
    	def get(self, request, pk):
    		book = Book.objects.get(pk=pk)
    		# 构建序列化对象,将模型对象传入,将其转换为json格式字符串
    		# serializer = BookInfoSerializer(instance=book)
    		serializer = BookInfoSerializer(book)
    

    创建对象
    当我们传递一个参数并指名对象为data时,默认做反序列化验证,示意创建

    # views.py
    
    import json
    
    from books.serializers import BookInfoSerializer
    
    class BooksView(View):
    	def post(self, request):
    		# 获取前端传递的json数据
    		json_bytes = request.body  # 默认或渠道字节类型数据
    		json_str = json_bytes.decode()  # 将其转换为字符类型
    		book = json.loads(json_str)  # 将json数据转换为字典
    		# 进行字段校验
    		serializer = BookInfoSerializer(data=book)
    		# 校验成功的数据保存在 serializer.validated_data 中,是一个有序字典对象
    		# print(serializer.validated_data)
    		# 判断校验是否成功,校验失败时抛出异常,终止往下执行
    		success = serializer.is_valid(raise_exception=True)
    		if success:
    			# 重点强调:此处save会调用序列化器中的create()方法,此方法需要我们自己定义实现
    			serializer.save()		
    		# 我们也可以直接在此处进行保存操作
    		# BookInfo(**serializer.validated_data).save()
    	else:
    		print(serializer.error)	
    

    from rest_framework import serializers
    
    from books.models import BookInfo
    
    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)
        logo = serializers.ImageField(label='图片', required=False)
        
        def create(self, validated_data):
            # validated_data: 校验成功的数据
            book_info = BookInfo(**validated_data).save()
            # 重点强调,此处必须返回保存成功后的对象
            return book_info
    

    更新对象
    接下来示意更新操作

    # serializers.py
    
    class BookView(View):
        def put(self, request, pk):
            try:
                book = BookInfo.objects.get(pk=pk)
            except Exception as e:
                raise Http404   
            # 获取前端传递的json数据
            json_bytes = request.body  # 默认或渠道字节类型数据
            json_str = json_bytes.decode()  # 将其转换为字符类型
            book_dict = json.loads(json_str)  # 将json数据转换为字典
    
            # 进行字段校验, 当instance和data同时传递时表示修改操作
            # partial=True 表示前端并不需要将所有字段都传递回来,可以选择性传递要修改的字段
            serializer = BookInfoSerializer(instance=book, data=book_dict, partial=True)
            success = serializer.is_valid(raise_exception=True)
    
            if success:
                # 重点强调:此处save会调用序列化器中的update()方法,此方法需要我们自己定义实现
                serializer.save()
    
            return HttpResponse('update success')
    

    # serializers.py
    
    from rest_framework import serializers
    
    from books.models import BookInfo
    
    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)
        logo = serializers.ImageField(label='图片', required=False)
        
        def create(self, validated_data):
            # validated_data: 校验成功的数据
            book_info = BookInfo(**validated_data).save()
            # 重点强调,此处必须返回保存成功后的对象
            return book_info
    
        def update(self, instance, validated_data):
            """更新,instance为要更新的对象实例"""
            # 说明,当用户更新时,并不一定更新所有字段,所以,用户未传递过来进行更新的字段我们将其原有的数据进行填充
            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)
            instance.logo = validated_data.get('logo', instance.logo)
            instance.save()
        	return instance
    

    serializer.save()源码解析

    def save(self, **kwargs):
        validated_data = dict(
             list(self.validated_data.items()) +
             list(kwargs.items())
         )
    
         # self 即我们创建的序列化器的实例对象
         # self.instance 即我们传递的对象
         # serializer = BookInfoSerializer(data=book)
         # 当我们传递了instance对象,则调用update方法进行数据更新
         if self.instance is not None:
             self.instance = self.update(self.instance, validated_data)
             assert self.instance is not None, (
                 '`update()` did not return an object instance.'
             )
         # 当我们没有传递instance对象时,则调用create方法进行对象创建
         else:
             self.instance = self.create(validated_data)
             assert self.instance is not None, (
                 '`create()` did not return an object instance.'
             )
    
     	return self.instance
    
    1. 自定义校验
      需求1:要求传递过来的书名必须包含 django,那么此时我们就必须自定义验证器
      1
      单独字段的验证器定义validate_<field_name>

    # serializers.py
    
    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)
        
        def validate_btitle(self, value):
            # value:前端传递过来存储在字典中的数据
            if 'django' not in value.lower():
                raise serializers.ValidationError("图书不是关于Django的")
            return value
    

    需求2:提交的数据中阅读量必须大于评论量,否则不让提交,给出错误
    1
    同时对多个字段进行比较验证时,可以定义validate方法来验证

    # serializers.py
    
    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)
        
        def validate(self, attrs):
            # attrs:前端传递过来存储在字典对象
            bread = attrs['bread']
            bcomment = attrs['bcomment']
            if bread < bcomment:
                raise serializers.ValidationError('阅读量小于评论量')
            return attrs
    

    需求3:要求传递过来的出版日期必须小于当前日期
    1
    通过validators参数自定义验证器函数

    # serializers.py
    
    from django.utils import timezone
    
    from rest_framework import serializers
    
    def bpub_date(value):
        if value > timezone.now().date():
            raise serializers.ValidationError("出版日期大于当前时间")
    	return value
    
    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, validators=[bpub_date])
        bread = serializers.IntegerField(label='阅读量', required=False)
        bcomment = serializers.IntegerField(label='评论量', required=False)
    

    UniqueValidator唯一性检验

    # serializers.py
    
    from django.utils import timezone
    
    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)
        # 该字段不允许重复
        btitle = serializers.CharField(label='名称', max_length=20, validators=[UniqueValidator])
        bpub_date = serializers.DateField(label='发布日期', required=False, validators=[])
        bread = serializers.IntegerField(label='阅读量', required=False)
        bcomment = serializers.IntegerField(label='评论量', required=False)
    

    UniqueTogetherValidation联合唯一

    # serializers.py
    
    from django.utils import timezone
    
    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)
        # 该字段不允许重复
        btitle = serializers.CharField(label='名称', max_length=20)
        bpub_date = serializers.DateField(label='发布日期', required=False, validators=[])
        bread = serializers.IntegerField(label='阅读量', required=False)
        bcomment = serializers.IntegerField(label='评论量', required=False)
        
        class Meta:
            # 要求书名和出版日期不能同时一致
            validators = [
                UniqueTogetherValidator(
                    fields=('btitle', 'bpub_date')
                )
            ]
    
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  • 原文地址:https://www.cnblogs.com/dongjiaxing/p/13887698.html
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