python - Django Admin - 如何禁止创建已经存在的对象

Question

我有一个模型:

class Category(models.Model):
CATS = (
    ('CT', 'Cool Things'),
    ('II', 'Internet & IT'),
    ('BT', 'Beautiful Things'),
)
cat = models.CharField(max_length=2, choices=CATS)
def __unicode__(self):
    return self.get_cat_display()

我已经为所有三个类别创建了对象。现在我想禁止我的同事创建另一个已经存在的对象。这怎么可能？我用谷歌搜索但似乎找不到一些东西......

Answer 1

为 cat 字段设置 unique=True ( docs ):

This is enforced at the database level and by model validation. If you try to save a model with a duplicate value in a unique field, a django.db.IntegrityError will be raised by the model’s save() method.

cat = models.CharField(max_length=2, choices=CATS, unique=True)