如何从数据库中检索的用户名？

Question

请帮助解决错误

我添加到站点和访问授权系统的用户配置文件。每个用户都有更改登录的能力。为此，他必须在以下表格输入登录并点击提交：

from django import forms 
from userprofile.models import UserProfile 
from django.contrib.auth.models import User 
from django.conf import settings 
import os 


class UserProfileForm (forms.ModelForm): 
class Meta: 
model = UserProfile 
fields = ('family', 'name', 'nation', 'status', 'login', 'nation_show') 

def clean_family (self): 
family = self.cleaned_data ['family'] 
letters_quantity = len (family) 
if letters_quantity < 4 : 
raise forms.ValidationError (" little beech in the name! ") 

return family 

def clean_login (self): 
login = self.cleaned_data ['login']. strip() 
if login! ='': 
login_form_db = User.objects.filter (username = 'qwe') 
if login_form_db: 
login_form_db = login_form_db.username 



if login == login_form_db: 
raise forms.ValidationError (" this username is busy ") 
else: 
User.username = login 
User.save (self) 

return login 

但最终我得到以下信息的错误：

AttributeError at/userprofile/
'QuerySet' object has no attribute 'username' 
Request Method: POST 
Request URL: http://127.0.0.1:8000/userprofile/ 
Django Version: 1.6.2 
Exception Type: AttributeError 
Exception Value: 
'QuerySet' object has no attribute 'username' 
Exception Location: c: \ Python33 \ django_projects \ mutants \ userprofile \ forms.py in clean_login, line 26 

Answer 1

filter()返回的查询集。由于您需要通过用户名获取User对象，因此请使用get()代替：

login_form_db = User.objects.get(username='qwe')