我正在尝试学习 django。刚刚开始一个项目。 目前已有 2 个应用程序。
我正在尝试通过 CMD 来完成此操作。它显示了以下问题。实际上，我正在尝试遵循 django 项目的教程。我查了一下，代码中没有使用UNIQUE关键字。我什至尝试删除然后保存但没有解决。
Employee :--
**models.py (employee) : **
from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver
# Create your models here.
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
designation = models.CharField(max_length=20, null=False, blank=False)
salary = models.IntegerField(null=True,blank=True)
class Meta:
ordering = ('-salary',) #minus sign indicates that we need the result in decending
order
def __str__(self):
return "{0} {1}". format(self.user.first_name, self.user.last_name)
@receiver(post_save, sender=User)
def user_is_created(sender, instance, created, **kwargs):
if created:
Profile.object.create (user=instance.)
else:
instance.profile.save()
Poll :--
**models.py (poll)**
from django.db import models
from django.contrib.auth.models import User
# Create your models here.`
`class Question(models.Model): # models.Model is the base model. we just need to extend it.
#All the class varibales will be considered as the columns of the table.
title = models.TextField(null=True, blank = True)
status = models.CharField(default = 'inactive', max_length=10) #if we don't pass anything it
will take 'inactive' as default
created_by = models.ForeignKey(User, null=True, blank=True, on_delete=models.CASCADE)
start_date = models.DateTimeField(null=True, blank=True)
end_date = models.DateTimeField(null=True, blank=True)
created_at = models.DateTimeField(auto_now_add=True) # done only once
updated_at = models.DateTimeField(auto_now=True) #Updated every time. If we want to track
when the object was modified last
def __str__(self):
return self.title
class Choice(models.Model):
question = models.ForeignKey('poll.Question', on_delete=models.CASCADE) #Quesion is
available in the model itself
text = models.TextField(null=True, blank=True)
created_at = models.DateTimeField(auto_now_add=True) # done only once
updated_at = models.DateTimeField(auto_now=True) #Updated every time. If we want to track
when the object was modified last
def __str__(self):
return self.text` ----------------------------------------------------------------------------------------------
**Error in commnad prompt :**
>>> u = User()
>>> u.save()
Traceback (most recent call last):
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\sqlite3\base.py", line 328, in
execute
return super().execute(query, params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sqlite3.IntegrityError: UNIQUE constraint failed: auth_user.username
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "C:\Users\kanha\V3.11\Lib\site-packages\django\contrib\auth\base_user.py", line 76, in save
super().save(*args, **kwargs)
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\base.py", line 814, in save
self.save_base(
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\base.py", line 877, in save_base
updated = self._save_table(
^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\base.py", line 1020, in _save_table
results = self._do_insert(
^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\base.py", line 1061, in _do_insert
return manager._insert(
^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\manager.py", line 87, in
manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\query.py", line 1805, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\models\sql\compiler.py", line 1822, in
execute_sql
cursor.execute(sql, params)
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 102, in execute
return super().execute(sql, params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 67, in execute
return self._execute_with_wrappers(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 80, in
_execute_with_wrappers
return executor(sql, params, many, context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 84, in _execute
with self.db.wrap_database_errors:
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\utils.py", line 91, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\kanha\V3.11\Lib\site-packages\django\db\backends\sqlite3\base.py", line 328, in
execute
return super().execute(query, params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
django.db.ut`ils.IntegrityError: UNIQUE constraint failed: auth_user.username
主要问题是您已经创建了空的用户字段
User()django.db.ut`ils.IntegrityError：唯一约束失败：auth_user.username
所以，尝试创建一个带有字段的用户对象
u = User(email='[email protected]' password='password123' other fields...)