Django：为数据库中的现有条目生成slug字段数据

不久前，我创建了一个Django模型：

class Product(models.Model):
    name = models.CharField(verbose_name=_('Nome'), max_length=100)
    description = models.CharField(verbose_name=_('Descrizione'), blank=True, default="")

现在我想插入一个slug字段：

class Product(models.Model):
    name = models.CharField(verbose_name=_('Nome'), max_length=100)
    slug = AutoSlugField(populate_from='name', unique=True)
    description = models.CharField(verbose_name=_('Descrizione'), blank=True, default="")

我的问题是，当我创建迁移时，Django要求我为slug字段插入一个默认值

我的想法是在迁移过程中为数据库中的现有条目生成一个slug，有什么办法吗

---

谢谢

这是我在相同情况下的代码

型号.py：

slug = AutoSlugField(null=True, default=None, unique=True, populate_from='name')

def migrate_data_forward(apps, schema_editor):
    for instance in MyModel.objects.all():
        print "Generating slug for %s"%instance
        instance.save() # Will trigger slug update

def migrate_data_backward(apps, schema_editor):
    pass

class Migration(migrations.Migration):
...

    operations = [
        migrations.AddField(
            model_name='my_model',
            name='slug',
            field=autoslug.fields.AutoSlugField(null=True, default=None, editable=False, populate_from='name', unique=True),
            preserve_default=False,
        ),
        migrations.RunPython(
            migrate_data_forward,
            migrate_data_backward,
        ),
    ]

请注意null=True，它与唯一字段兼容 在我的迁移中，我通过手动编辑迁移文件来添加数据迁移

0007\u my\u migration.py：

slug = AutoSlugField(null=True, default=None, unique=True, populate_from='name')

def migrate_data_forward(apps, schema_editor):
    for instance in MyModel.objects.all():
        print "Generating slug for %s"%instance
        instance.save() # Will trigger slug update

def migrate_data_backward(apps, schema_editor):
    pass

class Migration(migrations.Migration):
...

    operations = [
        migrations.AddField(
            model_name='my_model',
            name='slug',
            field=autoslug.fields.AutoSlugField(null=True, default=None, editable=False, populate_from='name', unique=True),
            preserve_default=False,
        ),
        migrations.RunPython(
            migrate_data_forward,
            migrate_data_backward,
        ),
    ]

---

这是不是

AutoSlugField

a

default

param？这是个好问题，尽管您可以使用migrations.RunPython.noop来向后函数！要创建空迁移：

python manage.py makemigrations——清空您的应用程序名称