起因
修改了表结构以后执行python3 manage.py migrate 报错:
django.db.utils.OperationalError: (1091, "Can't DROP 'email'; check that column/key exists")
所以进数据库把对应的表删除了,想着重新生成这张表.
删除表以后执行:
python3 manage.py makemigrations
python3 manage.py migrate
还是不能生成表,提示:No changes detected
处理过程
首先删除了app对应目录下的数据库对应的文件和缓存文件:
$ rm -rf migrations/ __pycache__/
重新执行:
$ python3 manage.py makemigrations
No changes detected
$~/code/django/blogproject$ python3 manage.py makemigrations comments
Migrations for 'comments':
comments/migrations/0001_initial.py
- Create model Comment
$~/code/django/blogproject$ python3 manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, blog, comments, contenttypes, sessions, users
Running migrations:
No migrations to apply.
进入数据库发现仍然没有生成表.
然后发现有一张django_migrations表,里面记录这有关创建表的记录,删除对应的数据表:
delete from django_migrations where app='yourappname';
重新执行生成数据库命令:
$ python3 manage.py makemigrations comments
No changes detected in app 'comments'
$~/code/django/blogproject$ python3 manage.py migrate comments
Operations to perform:
Apply all migrations: comments
Running migrations:
Applying comments.0001_initial... OK
数据表顺利生成.
结论
在执行
python3 manage.py makemigrations python3 manage.py migrate
操作的时候,不仅会创建0001_initial.py对应的模型脚本,还会创建一个数据库记录创建的模型.如果想重新生成数据库,需要两个地方都做删除.
以上这篇解决Django migrate No changes detected 不能创建表的问题就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持天达云。