Postgres抱怨不存在约束

Question

我正在迁移postgresql中的数据库模式，我在Django（1.11.11）中收到此错误：

        django.db.utils.ProgrammingError: constraint 
"djstripe_charge_account_id_597fef70_fk_djstripe_account_id" for relation "djstripe_charge" already exists

但是在ALTER TABLE djstripe_charge DROP CONSTRAINT djstripe_charge_account_id_597fef70_fk_djstripe_account_id ;中执行psql会出现以下错误：

ERROR:  constraint "djstripe_charge_account_id_597fef70_fk_djstripe_account_id"
 of relation "djstripe_charge" does not exist

我在psql中使用\d djstripe_charge进行了验证，并且没有显示在关系列表

上

在django中，迁移代码中出现错误（90％肯定）：

    migrations.AddField(
        model_name='charge',
        name='account',
        field=models.ForeignKey(help_text='The account the charge was made on behalf of. Null here indicates that this value was never set.', null=True, on_delete=django.db.models.deletion.CASCADE, related_name='charges', to='djstripe.Account'),
    ),

为什么Django抱怨这个？