Django之DRF框架三，序列化组件

一、序列化类的常用字段和字段参数

常用字段

字段名字段参数CharFieldmax_length=None, min_length=None, allow_blank=False, trim_whitespace=TrueIntegerFieldmax_value=None, min_value=NoneFloatFieldmax_value=None, min_value=NoneBooleanFieldNullBooleanFieldFloatFieldmax_value=None, min_value=NoneDecimalFieldmax_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None 注：max_digits: 最多位数 decimal_palces: 小数点位置TimeFieldformat=api_settings.TIME_FORMAT, input_formats=NoneDateFieldformat=api_settings.DATE_FORMAT, input_formats=NoneDateTimeFieldformat=api_settings.DATETIME_FORMAT, input_formats=None)EmailFieldmax_length=None, min_length=None, allow_blank=FalseRegexFieldregex, max_length=None, min_length=None, allow_blank=FalseSlugFieldmax_length=50, min_length=None, allow_blank=False)，正则字段，验证正则模式 [a-zA-Z0-9-]+URLFieldmax_length=200, min_length=None, allow_blank=FalseUUIDFieldformat=’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”IPAddressFieldprotocol=’both’, unpack_ipv4=False, **options)DurationFieldChoiceFieldchoices，choices与Django的用法相同MultipleChoiceFieldchoicesFileFieldmax_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URLImageFieldmax_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URLListFieldchild=, min_length=None, max_length=NoneDictFieldchild= 常用字段参数

CharField及子类的（EmailField） 反序列化的校验，字段自己的规则

参数含义max_length最大长度min_lenght最小长度allow_blank是否允许为空trim_whitespace是否截断空白字符

IntegerField

参数含义max_value最小值max_value最大值

字段共有参数

参数含义required表明该字段在反序列化时必须输入，默认Truedefault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Falsevalidators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read_only表明该字段仅用于序列化输出，默认Falsewrite_only表明该字段仅用于反序列化输入，默认False 二、序列化高级用法之source(了解)

首先先创建一个django项目，创建book表、publish表、以及author表，并建立三个表之间的关系，完成模型表数据的迁移并录入数据

from django.db import models # Create your models here. class Book(models.Model): name = models.CharField(max_length=32) price = models.DecimalField(max_digits=5, decimal_places=2) # 外键字段书与出版社一对多，关联字段在多的一方 publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE) # 书与作者多对多，需要创建中间表，使用全自动创建第三张表 authors = models.ManyToManyField(to='Author') class Publish(models.Model): name = models.CharField(max_length=32) addr = models.CharField(max_length=64) class Author(models.Model): name = models.CharField(max_length=32) phone = models.IntegerField()

序列化字段名

sourse

可以定制序列化字段名防止数据被人篡盗，将前端展示的字段名和后端数据的字段名设置成不同的字段名

sourse序列化自有字段和关联字段的区别

1.自有字段，直接写表字段名 publish_name = serializers.CharField(max_length=12, min_length=3, required=True, allow_blank=True,source='name') 2.还可以直接映射方法 models.py class Publish(models.Model): name = models.CharField(max_length=32) addr = models.CharField(max_length=64) def sb_name(self): return self.name+'sb' serializer.py publish_name = serializers.CharField(max_length=12, min_length=3, required=True, allow_blank=True,source='sb_name') 3.关联字段 通过外键获取 一对多 一对多的关联，直接点 publish=serializers.CharField(max_length=8,source='publish.name') 多对多 source不能用实现定制序列化关联表的字段 authors = serializers.CharField(source='authors.all') 作业之装饰器 def outer(func): def inner(request, *args, **kwargs): try: request.data = json.loads(request.body) # 如果json格式不可以序列化loads except Exception as e: request.data = request.POST if request.method == 'PUT': body_in = str(request.body, encoding='utf-8') # 转 译 body_in = parse.unquote(body_in) # request.data = {i.split('=')[0]: i.split('=')[1] for i in body_in.split('&')} # 字典推导式 # 笨方法 d = {} sp_1 = body_in.split('&') for i in sp_1: k, v = i.split('=') d[k] = v request.data = d res = func(request, *args, **kwargs) return res return inner @outer def index(request): print(request.data) return JsonResponse({'code': '请求成功'}) 该装饰器只针对视图函数，如果要装饰在类的方法上就需要添加形参中添加self参数 作业之用户一次性提交数据 views.py from .serializer import AuthorSerializer class AuthorView(APIView): def post(self, request): ser = AuthorSerializer(data=request.data) if ser.is_valid(): ser.save() return Response({'code': 100, 'msg': '创建成功'}) else: return Response({'code': 100, 'msg': ser.errors}) serializer.py class AuthorSerializer(serializers.ModelSerializer): telephone = serializers.CharField() birthday = serializers.CharField() addr = serializers.CharField() class Meta: model = Author fields = ['name', 'age', 'telephone', 'birthday', 'addr'] def create(self, validated_data): # 因为author表里没有authordetail其它三个字段，需要重写 telephone = validated_data.pop('telephone') birthday = validated_data.pop('birthday') addr = validated_data.pop('addr') # 先创建作者详情，在创建作者，因为外键字段的约束，是现有作者详情，再有作者约束 author_detail = AuthorDetail.objects.create(telephone=telephone, birthday=birthday, addr=addr) validated_data['author_detail'] = author_detail author = Author.objects.create(**validated_data) return author