类型错误：运行迁移或运行测试时需要一个整数（获取类型 str）

Question

我修改了一个现有模型，如下所示：

最初是这样的

class AppAssessment(models.Model):
    contact_uuid = models.CharField(max_length=255)
    step = models.IntegerField(null=True)
    optionId = models.IntegerField(null=True, blank=True)
    user_input = models.TextField(null=True, blank=True)
    title = models.TextField(null=True, blank=True)
    description = models.TextField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return (
            f"UUID: {self.contact_uuid} | Step: {self.step} | OptionID: {self.optionId} \n"
            f"| User_Input: {self.user_input} | Title: {self.title} \n"
            f"| Created_at: {self.created_at}"
                        
        )

但我将 contact_uuid 更改为 contact_id 并更改了模型类型：

class AppAssessment(models.Model):
    contact_id = models.UUIDField()
    step = models.IntegerField(null=True)
    optionId = models.IntegerField(null=True, blank=True)
    user_input = models.TextField(null=True, blank=True)
    title = models.TextField(null=True, blank=True)
    description = models.TextField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return (
            f"UUID: {self.contact_id} | Step: {self.step} | OptionID: {self.optionId} \n"
            f"| User_Input: {self.user_input} | Title: {self.title} \n"
            f"| Created_at: {self.created_at}"
                        
        )

在views.py 中，我已经将条目存储为字符串，

        store_url_entry = AppAssessment(contact_uuid=contact_uuid, title=title, description=description, step=step, user_input=value, optionId=optionId)
        store_url_entry.save()

我删除了数据库并重新创建了它，但它仍然失败。我还重新启动了虚拟环境，但没有帮助。

我看到的错误是这样的：

  /home/osboxes/app-hub/venv/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
No changes detected
/home/osboxes/app-hub/venv/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
Operations to perform:
  Apply all migrations: app, admin, auth, authtoken, changes, contenttypes, eventstore, registrations, sessions
Running migrations:
  Applying app.0021_auto_20220413_0328...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/base.py", line 323, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 234, in handle
    fake_initial=fake_initial,
  File "/home/osboxes/app-hub/venv/lib/python3.6/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 "/home/osboxes/app-hub/venv/lib/python3.6/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 "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/migrations/operations/fields.py", line 112, in database_forwards
    field,
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 433, in add_field
    definition, params = self.column_sql(model, field, include_default=True)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 161, in column_sql
    default_value = self.effective_default(field)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 233, in effective_default
    return field.get_db_prep_save(self._effective_default(field), self.connection)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 793, in get_db_prep_save
    return self.get_db_prep_value(value, connection=connection, prepared=False)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 2333, in get_db_prep_value
    value = self.to_python(value)
  File "/home/osboxes/app-hub/venv/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 2343, in to_python
    return uuid.UUID(**{input_form: value})
  File "/usr/local/lib/python3.6/uuid.py", line 137, in __init__
    hex = hex.replace('urn:', '').replace('uuid:', '')
TypeError: an integer is required (got type str)

App.0021_auto_20220413_0328 的迁移文件：

# Generated by Django 2.2.20 on 2022-04-13 03:28

from django.db import migrations, models
import django.utils.timezone


class Migration(migrations.Migration):

    dependencies = [
        ('app', '0020_auto_20220411_1610'),
    ]

    operations = [
        migrations.RemoveField(
            model_name='appassessment',
            name='contact_uuid',
        ),
        migrations.AddField(
            name='contact_id',
            field=models.UUIDField(default=django.utils.timezone.now),
            preserve_default=False,
        ),
    ]

感谢您的帮助。

Answer 1

我认为问题出在您的迁移文件...这一行...

field = models.UUIDField(default=django.utils.timezone.now)

因为您尝试使用 timezone.now() 填充 UUID 字段。
因此，如果这个迁移文件对您来说不重要，只需删除它（如果该记录存​​在，您还需要从数据库中删除它的记录，即 django_migrations 表），或者如果这只是一个测试环境，您可以简单地从您的数据库中删除所有内容数据库并进行 makemigrations 并再次迁移（删除此迁移文件后 -> app.0021_auto_20220413_0328）。

重要提示：如果您想为 UUID 字段提供默认值，您应该使用类似的内容（在进行 makemigrations 和 migrate 之前）：

from uuid import uuid4

contact_id = models.UUIDField(default=uuid4)

因为您的表中有一些记录，并且您正在尝试添加 UUID字段没有默认值...那么 Django 会要求默认值，恐怕当 Django 询问类似以下内容时，没有任何其他方法可以在默认值中提供 uuid4() ：

Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit, and let me add a default in models.py

另请注意，如果您的记录在您的旧字段（contact_uuid）对您很重要，并且您想将其值添加到新字段（contact_id）中，您应该编写一个自定义迁移文件，这是另一个故事。