问题

INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.env] No changes in schema detected.

解决

将models文件导入，就可以识别

from gevent import monkey;monkey.patch_all()
from web import create_app, db , models
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand

app = create_app()
manager = Manager(app)
Migrate(app=app, db=db)
manager.add_command('db', MigrateCommand)


@manager.command
def runserver_gevent():
    from gevent import pywsgi
    server = pywsgi.WSGIServer(("127.0.0.1", 5000), app)
    server.serve_forever()


if __name__ == '__main__':
    manager.run()

重新迁移

删掉迁移文件再次迁移

python manage.py db init
python manage.py db migrate
python manage.py db upgrade