起因

同步表的过程中，我手动将数据库中的一个表删除了，此时再去执行命令，发现不能再数据库中新建表了
修改了表结构以后执行python3 manage.py migrate 报错:

No changes detected

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.

然后，删除app下面目录migrations下面除了init.py其他的所有文件

image.png

最后，删除migrations中关于你的app的同步数据数据库记录

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.