我有一个这样的模特:
class AssignedTip(models.Model):
"""Model representing a tip (but not a specific copy of a tip)."""
user = models.ForeignKey(User, on_delete=models.CASCADE)
date = models.DateField(null=True)
note = models.CharField(max_length=50, default="Tip")
amount = models.FloatField()
minutes = models.FloatField(default=0)
class Meta:
unique_together = ('user', 'date',)
所以有一个唯一的限制是user+date.
现在，我想将新数据插入到表中.但是，如果唯一约束匹配，它应该更新对象，而不是创建新对象.我怎么能这么做.使用create_or_update会给我一个错误，并且不会更新项目.如果约束匹配，我如何告诉它更新？:
AssignedTip.objects.update_or_create(user=User.objects.get(id=user), amount=user_amount, date=day.date(), minutes=minutes)
我得到了这个错误:
Environment:
Request Method: GET
Request URL: http://0.0.0.0:8000/tasks/
Django Version: 4.0.8
Python Version: 3.10.12
Installed Applications:
['django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'widget_tweaks',
'tasks.apps.TasksConfig',
'tips.apps.TipsConfig',
'ratings.apps.RatingsConfig',
'procedures.apps.ProceduresConfig',
'inventory.apps.InventoryConfig',
'registration.apps.RegistrationConfig',
'ckeditor',
'crispy_forms',
'crispy_bootstrap4',
'django_crontab']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
'whitenoise.middleware.WhiteNoiseMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'login_required.middleware.LoginRequiredMiddleware']
Traceback (most recent call last):
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 657, in get_or_create
return self.get(**kwargs), False
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 496, in get
raise self.model.DoesNotExist(
During handling of the above exception (AssignedTip matching query does not exist.), another exception occurred:
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/sqlite3/base.py", line 477, in execute
return Database.Cursor.execute(self, query, params)
The above exception (UNIQUE constraint failed: tips_assignedtip.user_id, tips_assignedtip.date) was the direct cause of the following exception:
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/core/handlers/exception.py", line 55, in inner
response = get_response(request)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/raphael/development/iaro/iaroapp/tasks/views.py", line 86, in index
assignTips(datetime.today().replace(day=7))
File "/home/raphael/development/iaro/iaroapp/iaroapp/cron.py", line 71, in assignTips
AssignedTip.objects.update_or_create(user=User.objects.get(id=user), amount=user_amount, date=day.date(), minutes=minutes)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 684, in update_or_create
obj, created = self.select_for_update().get_or_create(defaults, **kwargs)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 664, in get_or_create
return self.create(**params), True
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 514, in create
obj.save(force_insert=True, using=self.db)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/base.py", line 806, in save
self.save_base(
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/base.py", line 857, in save_base
updated = self._save_table(
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/base.py", line 1000, in _save_table
results = self._do_insert(
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/base.py", line 1041, in _do_insert
return manager._insert(
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/query.py", line 1434, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/models/sql/compiler.py", line 1621, in execute_sql
cursor.execute(sql, params)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 103, in execute
return super().execute(sql, params)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 67, in execute
return self._execute_with_wrappers(
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 80, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 84, in _execute
with self.db.wrap_database_errors:
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/utils.py", line 91, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
File "/home/raphael/.conda/envs/iaro/lib/python3.10/site-packages/django/db/backends/sqlite3/base.py", line 477, in execute
return Database.Cursor.execute(self, query, params)
Exception Type: IntegrityError at /tasks/
Exception Value: UNIQUE constraint failed: tips_assignedtip.user_id, tips_assignedtip.date