Django修改模型字段后migrate报错ValueError：无法引用列表参数

问题场景 #

将Hotel模型的people字段从PostgreSQL专属的ArrayField改为CharField后，执行migrate命令时触发错误。

当前模型代码 #

class Hotel(models.Model):
    name = models.CharField(max_length=255)
    address = models.CharField(max_length=255)
    check_in_date = models.DateField()
    check_out_date = models.DateField()
    notes = models.TextField(blank=True)
    id = models.AutoField(primary_key=True)
    people = models.CharField(max_length=255)

    def __str__(self):
        return self.name + ", " + str(self.id)

相关迁移文件 #

0007（添加ArrayField）：

class Migration(migrations.Migration):

    dependencies = [
        ('project_name', '0006_confirmationentry_alter_hotel_notes'),
    ]

    operations = [
        migrations.AddField(
            model_name='hotel',
            name='people',
            field=django.contrib.postgres.fields.ArrayField(base_field=models.IntegerField(), default=list, size=None),
        ),
    ]

0008（改为CharField）：

class Migration(migrations.Migration):

    dependencies = [
        ('project_name', '0007_hotel_people'),
    ]

    operations = [
        migrations.AlterField(
            model_name='hotel',
            name='people',
            field=models.CharField(max_length=255),
        ),
    ]

迁移错误信息 #

Applying project_name.0007_hotel_people...Traceback (most recent call last):
  File "/Users/me/Desktop/project_name/manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/base.py", line 414, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/base.py", line 460, in execute
    output = self.handle(*args, **options)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/base.py", line 98, in wrapped
    res = handle_func(*args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/core/management/commands/migrate.py", line 290, in handle
    post_migrate_state = executor.migrate(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/migrations/executor.py", line 131, in migrate
    state = self._migrate_all_forwards(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/migrations/executor.py", line 163, in _migrate_all_forwards
    state = self.apply_migration(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/migrations/executor.py", line 248, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/migrations/migration.py", line 131, in apply
    operation.database_forwards(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/migrations/operations/fields.py", line 108, in database_forwards
    schema_editor.add_field(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/backends/sqlite3/schema.py", line 381, in add_field
    self._remake_table(model, create_field=field)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/backends/sqlite3/schema.py", line 229, in _remake_table
    mapping[create_field.column] = self.quote_value(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/django/db/backends/sqlite3/schema.py", line 68, in quote_value
    raise ValueError(
ValueError: Cannot quote parameter value [] of type <class 'list'>

错误原因 #

• ArrayField是PostgreSQL专属字段，SQLite不支持该字段类型。
• 迁移执行时会按顺序先执行0007（添加ArrayField），此时SQLite无法处理ArrayField的默认值[]（list类型），直接抛出类型引用错误。

解决步骤 #

1. 合并迁移操作（最直接方法） #

• 删除0007和0008这两个迁移文件。
• 确保models.py中people字段保持为CharField。
• 重新生成迁移文件：

  python3 manage.py makemigrations
  

• 执行迁移：

  python3 manage.py migrate
  

2. 确认SQLite数据库配置 #

检查项目settings.py中的数据库配置，确保使用SQLite：

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

若之前配置过PostgreSQL，替换为上述配置即可。

3. 回退已有迁移记录（若已执行过0007） #

如果数据库中已经记录了0007的迁移记录，先回退到0006版本：

python3 manage.py migrate project_name 0006

之后再删除0007、0008，重新生成并执行迁移。

内容的提问来源于stack exchange，提问作者temi a