Question

我为Django项目设置了两个数据库，一个MySQL和一个Postgres。

我已经安装了一个数据库路由器，并且一切正常，直到在Postgres模型中将CharField和max_length的值更改为300为止。

该模型在Postgres中，但是现在Django抛出有关MySQL的错误：

[postgres_app.TestModel.slug]: (mysql.E001) MySQL does not allow unique CharFields to have a max_length > 255.

我仔细检查了数据库路由器，一切看起来都很好。我还必须再次提到路由器之前已正确完成其工作，并选择了正确的数据库进行读取，写入和迁移。这是我的路由器：

POSTGRES_APPS = ['postgres_app']


class PostgresRouter(object):
    """ Controls which apps can have access to the postgres instance. """

    def db_for_read(self, model, **hints):
        """ Called on every read action on a model. """
        if model._meta.app_label in POSTGRES_APPS:
            return 'postgres'
        return None

    def db_for_write(self, model, **hints):
        """ Called on every write action on a model. """
        if model._meta.app_label in POSTGRES_APPS:
            return 'postgres'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        """ Called only on migrations. Only allow relations if both models are in POSTGRES_APPS. """
        return {obj1._meta.app_label, obj2._meta.app_label}.issubset(set(POSTGRES_APPS)) or None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        """ Called only on migrations. """
        if db == 'postgres':
            return app_label in POSTGRES_APPS
        else:
            return app_label not in POSTGRES_APPS

这是我的模型：

class TestModel(models.Model):
    slug = models.CharField(max_length=300, blank=True, null=True, unique=True)

所以问题是，这是否是Django中的错误，如果不是，那么如何告诉Django它正在查看错误的数据库。

Django在模型字段上为错误的数据库引发错误

0 个答案: