添加外键后 Django 迁移给出 "unknown column" 错误

Question

class Agent(models.Model):
    full_name = models.CharField(max_length=200)
    short_code = models.CharField(max_length=200)

class Phone(models.Model):
    date = models.DateTimeField('Call Time')
    ...
    // Newly added:
    agent = models.ForeignKey(Agent, on_delete=models.CASCADE)

我正在使用 mysql。添加外键后，makemigrations 命令就可以运行了。 python manage.py 迁移命令会给出错误：

  File "/Library/Python/2.7/site-packages/django/db/backends/mysql/base.py", line 112, in execute
    return self.cursor.execute(query, args)
  File "/Library/Python/2.7/site-packages/MySQLdb/cursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "/Library/Python/2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
django.db.utils.OperationalError: (1054, "Unknown column 'agent' in 'dash_phone'")

python manage.py sqlmigrate dash 0004 给出：

BEGIN;
--
-- Alter field agent on phone
--
ALTER TABLE `dash_phone` CHANGE `agent` `agent_id` integer NOT NULL;
ALTER TABLE `dash_phone` MODIFY `agent_id` integer NOT NULL;
CREATE INDEX `dash_phone_agent_id_e9e1c068_uniq` ON `dash_phone` (`agent_id`);
ALTER TABLE `dash_phone` ADD CONSTRAINT `dash_phone_agent_id_e9e1c068_fk_dash_agent_id` FOREIGN KEY (`agent_id`) REFERENCES `dash_agent` (`id`);

COMMIT;

Answer 1

嗯，这似乎是一个错误。 Django 在提交新代理字段之前将代理字段转换为外键。它以 ALTER TABLE ... CHANGE 开头，在它实际添加字段之前。

尝试分两步添加字段：

添加一个 IntegerField 代理字段（不是外键），makemigrations，migrate
将代理从整数字段更改为外键、makemigrations、migrate

考虑为这个问题开一个django ticket。

添加外键后 Django 迁移给出 "unknown column" 错误

Django migrate after adding foreign key gives "unknown column" error

mysql

django

migrate