假设这个模型:
from django.db import models
class DeviceInfo(models.Model):
device_id = models.IntegerField(primary_key=True)
def __str__(self):
return str(self.device_id)
class CenterCommands(models.Model):
device_object = models.ForeignKey(
DeviceInfo, on_delete=models.CASCADE)
command = models.CharField(max_length=512)
def __str__(self):
return str(self.device_object.device_id)
class CenterCommandsRawData(models.Model):
center_command = models.OneToOneField(
CenterCommands, on_delete=models.CASCADE, primary_key=True)
data = models.CharField(max_length=512)
def __str__(self):
return str(self.center_command.device_object.device_id)
python manage.py makemigrations deviceApp
和
python manage.py migrate
,我得到以下错误:
(myDjangoEnv) $>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, deviceApp, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying deviceApp.0001_initial...Traceback (most recent call last):
File "manage.py", line 21, in <module>
main()
File "manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line
utility.execute()
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\base.py", line 364, in execute
output = self.handle(*args, **options)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\core\management\commands\migrate.py", line 234, in handle
fake_initial=fake_initial,
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\migrations\executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\migrations\executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\migrations\executor.py", line 245, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\migrations\operations\models.py", line 92, in database_forwards
schema_editor.create_model(model)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\backends\base\schema.py", line 257, in create_model
definition, extra_params = self.column_sql(model, field)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\backends\base\schema.py", line 150, in column_sql
db_params = field.db_parameters(connection=self.connection)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 966, in db_parameters
return {"type": self.db_type(connection), "check": self.db_check(connection)}
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 963, in db_type
return self.target_field.rel_db_type(connection=connection)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 878, in target_field
return self.foreign_related_fields[0]
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 632, in foreign_related_fields
return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field)
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 619, in related_fields
self._related_fields = self.resolve_related_fields()
File "C:\Users\Masoud\Anaconda3\envs\myDjangoEnv\lib\site-packages\django\db\models\fields\related.py", line 604, in resolve_related_fields
raise ValueError('Related model %r cannot be resolved' % self.remote_field.model)
ValueError: Related model 'deviceApp.CenterCommands' cannot be resolved
以下是迁移文件:
# Generated by Django 2.2.3 on 2019-08-21 08:29
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
initial = True
dependencies = [
]
operations = [
migrations.CreateModel(
name='DeviceInfo',
fields=[
('device_id', models.IntegerField(primary_key=True, serialize=False)),
],
),
migrations.CreateModel(
name='CenterCommandsRawData',
fields=[
('center_command', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, primary_key=True, serialize=False, to='deviceApp.CenterCommands')),
('data', models.CharField(max_length=512)),
],
),
migrations.CreateModel(
name='CenterCommands',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('device_object', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='deviceApp.DeviceInfo')),
],
),
]
编辑:如注释中所述,可以通过手动更改迁移文件中模型的顺序来解决此问题。但我在想为什么会这样?我的模型定义正确吗?
我认为手动编辑迁移文件不是这里最好的选择。
