Python 为什么我的数据库迁移没有做任何事情?

Python 为什么我的数据库迁移没有做任何事情?,python,sqlalchemy,flask-sqlalchemy,alembic,Python,Sqlalchemy,Flask Sqlalchemy,Alembic,当我运行迁移时,它不会执行任何操作: ➔ python db_control.py db upgrade INFO [alembic.migration] Context impl PostgresqlImpl. INFO [alembic.migration] Will assume transactional DDL.

当我运行迁移时,它不会执行任何操作:

➔ python db_control.py db upgrade
INFO  [alembic.migration] Context impl PostgresqlImpl.
INFO  [alembic.migration] Will assume transactional DDL.