ModelSerializer字段验证以及序列化def validate_字段名(self, value),单⼀字段校验
from rest_framework import serializers
from rest_framework import exceptions
from .. import models
class BidModelSerializer(serializers.ModelSerializer):
username = serializers.CharField(source='user.nickname', read_only=True)
status_text = serializers.CharField(source='get_status_display', read_only=True)
class Meta:
model = models.BidRecord
exclude = ['user', 'status', ]
def validate_item(self, value):
""" 验证是否还正在拍卖"""
item_id = self.('item')
exists = models.AuctionItem.objects.filter(id=item_id, status=3).exists()
if not exists:
raise exceptions.ValidationError('拍卖商品不存在或已成交')
return value
def validate_price(self, value):
""" 验证价格
1. ⽐最⼤的要⼤
2. 是单元的倍数
"""
from dels import Max
item_id = self.('item')
item_object = models.AuctionItem.objects.filter(id=item_id).first()
if value < item_object.start_price:
raise exceptions.ValidationError('出价不能低于低价')
result = models.BidRecord.objects.filter(item_id=item_id).aggregate(max_price=Max('price'))
if not result['max_price']:
return value
if value <= result['max_price']:
raise exceptions.ValidationError('已有出价更⾼者,请调整出价')
return value
重构create⽅法
'''
这⾥应⽤了Serializer与ModelSerializer的结合使⽤
'''
class CreateNewsTopicModelSerializer(serializers.Serializer):
key = serializers.CharField()
cos_path = serializers.CharField()
class CreateNewsModelSerializer(serializers.ModelSerializer):
imageList = CreateNewsTopicModelSerializer(many=True)
class Meta:
model = models.News
exclude = ['user', 'viewer_count', 'comment_count']
def create(self, validated_data):
image_list = validated_data.pop('imageList')
news_object = models.ate(**validated_data)
data_list = models.NewsDetail.objects.bulk_create(
[models.NewsDetail(**info, news=news_object) for info in image_list]
)
news_object.imageList = data_list
if pic:
models.Topic.objects.filter(id=pic_id).update(count=F('count') + 1)
return news_object
⾃定义字段,获取⼀张表的全部内容
'''
此处涉及到两个ModelSerializer类
# 保证⾦
deposit = serializers.SerializerMethodField()
def get_deposit(self, obj):
return PayDepositModelSerializer(instance=obj.deposit).data
'''
class PayDepositModelSerializer(serializers.ModelSerializer):
# ⽀付保证⾦
deposit_text = serializers.CharField(source='get_deposit_type_display')
checked = serializers.BooleanField(default=False)
class Meta:
model = models.Collateral
fields = ['id', 'deposit_type', 'deposit_text', 'amount', 'balance', 'checked']
class PayModelSerializer(serializers.ModelSerializer):
user_balance = serializers.IntegerField(source='user.balance')
auction = serializers.CharField(source='lot.special_auction_id')
# 拍品
lot = serializers.SerializerMethodField()
# 保证⾦
deposit = serializers.SerializerMethodField()
# 是否有优惠券
coupon = serializers.SerializerMethodField()
# ⽀付⽅式
pay_method = serializers.SerializerMethodField()
class Meta:
model = models.Order
exclude = ['uid', 'twenty_four_task_id', 'user']
def get_deposit(self, obj):
return Pay DepositModelSerializer(instance=obj.deposit).data
def get_coupon(self, obj):
user_object = t['request'].user
exists = models.UserCoupon.objects.filter(
user=user_object, status=1, coupon__auction=obj.lot.special_auction_id).exists()        context = {
'id': None,
'has': exists,
'text': '请选择优惠券' if exists else '⽆',
'money': 0
}
return context
def get_pay_method(self, obj):
balance = t['request'].user.balance
info = {
'selected': 1,
'choices': [
{'id': 1, 'text': '余额(%s)' % balance},
{'id': 2, 'text': '⽀付'},
]
}
return info
def get_lot(self, obj):
return {
'title': obj.lot.name,
'cover': ver.name,
'uid': obj.lot.catalog_num
}
ModelSerializer序列化与反序列化(重点)
视图类
class UserV3APIView(APIView):
# 单查查
def get(self, request, *args, **kwargs):
pk = ('pk')
if pk:
user_obj = models.User.objects.filter(is_delete=False, pk=pk).first()
if not user_obj:
return Response({
'status': 1,
'msg': 'pk error',
}, status=400)
user_ser = serializers.UserModelSerializer(user_obj, many=False)
return Response({
'status': 0,
'msg': 'ok',
'results': user_ser.data
})
else:
user_query = models.User.objects.filter(is_delete=False).all()
user_ser = serializers.UserModelSerializer(user_query, many=True)
return Response({
'status': 0,
'msg': 'ok',
'results': user_ser.data
})
# 单增
def post(self, request, *args, **kwargs):
user_ser = serializers.UserModelSerializer(data=request.data)
if user_ser.is_valid():
# ⼊库
user_obj = user_ser.save()
return Response({
'status': 0,
'msg': 'ok',
'results': serializers.UserModelSerializer(user_obj).data
})
else:
return Response({
'status': 1,
'msg': s,
})
序列化类
""" ModelSerializer类序列化与反序列化总结
1)序列化类继承ModelSerializer,所以需要在配置类Meta中进⾏配置
2)model配置:绑定序列化相关的Model表
3)fields配置:采⽤插拔式设置所有参与序列化与反序列化字段
4)extra_kwargs配置:
划分系统字段为三种:只读(read_only)、只写(write_only)、可读可写(不设置)
字段是否必须:required
选填字段:在extra_kwargs进⾏配置,但不设置required,且有默认值
5)⾃定义序列化字段:
第⼀种(不提倡):在序列化类中⽤SerializerMethodField()来实现
第⼆种(提倡):在模型类中⽤@property来实现,可插拔
6)⾃定义反序列化字段:
同Serializer类,且规则只能在此声明中设置,或是在钩⼦中设置,在extra_kwargs中对其设置的⽆效⾃定义反序列化字段与系统字段,设置规则⼀样,所以必须设置 write_only
7)局部钩⼦,全局钩⼦同Serializer类
8)不需要重写create和update⽅法
"""
class UserModelSerializer(serializers.ModelSerializer):
# 第⼀种⾃定义序列化字段:该字段必须在fields中设置
# gender = serializers.SerializerMethodField()
# def get_gender(self, obj):
#    _sex_display()
# ⾃定义反序列化字段同Serializer类,且规则只能在此声明中设置,或是在钩⼦中设置,
#      在extra_kwargs中对其设置的⽆效
# 注:⾃定义反序列化字段与系统字段,设置规则⼀样,所以必须设置 write_only
re_password = serializers.CharField(min_length=3, max_length=16, write_only=True)
class Meta:
model = models.User
drop table if exists admin# fields采⽤插拔式设置所有参与序列化与反序列化字段
fields = ('username', 'gender', 'icon', 'password', 'sex', 're_password')
extra_kwargs = {
'username': {  # 系统字段不设置read_only和write_only,默认都参加
'min_length': 3,
'max_length': 10,
'error_messages': {
'min_length': '太短',
'max_length': '太长'
}
},
'gender': {
'read_only': True,  # ⾃定义的序列化字段默认就是read_only,且不能修改,可以省略
},
'password': {
'write_only': True,
},
'sex': {  # 像sex有默认值的字段,为选填字段('required': True可以将其变为必填字段)
'write_only': True,
# 'required': True
}
}
# 局部全局钩⼦同Serializer类,是与 Meta 同缩进的
def validate_username(self, value):
if 'g' in value.lower():
raise serializers.ValidationError('名字中不能有g')
return value
def validate(self, attrs):
password = ('password')
re_password = attrs.pop('re_password')
if password != re_password:
raise serializers.ValidationError({'re_password': '两次密码不⼀致'})
return attrs
# create和update⽅法不需要再重写,ModelSerializer类已提供,且⽀持所有关系下的连表操作
模型类
from django.db import models
class User(models.Model):
SEX_CHOICES = (
(0, '⼥'),
(1, '男'),
)
username = models.CharField(max_length=64, verbose_name='⽤户名', blank=True, unique=True)    password = models.CharField(max_length=64, verbose_name='密码')
sex = models.IntegerField(choices=SEX_CHOICES, default=0, verbose_name='性别')
img = models.ImageField(upload_to='img', default='img/default.png', verbose_name='头像')
# 开发中,数据不会直接删除,通过字段控制
is_delete = models.BooleanField(default=False, verbose_name='是否注销')
# 数据库数据⼊库,⼀般都会记录该数据第⼀次⼊库时间,有时候还会记录最后⼀次更新时间
created_time = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
# 第⼆种⾃定义序列化字段(插拔式,提倡使⽤)
@property
def gender(self):
_sex_display()
@property
def icon(self):
f import settings
return '%s%s%s' % (settings.BASE_URL, settings.MEDIA_URL, self.img)
class Meta:  # 配置类,给所属类提供配置信息
db_table = 'old_boy_user'
verbose_name_plural = '⽤户表'
def __str__(self):  # 不要在这⾥进⾏连表操作,⽐如admin页⾯可能会崩溃
return self.username