flask_migration迁移时类是布尔型，迁移后是长整型。

我看的是flask-web开发那本书。
命令是：
migrate = Migrate(app, db)
manager.add_command('db', MigrationCommand)
python hello.py db migrate db init
python hello.py db migrate -m "initial migration"
python hello.py db upgrade
最好能给一个如何让迁移后是布尔型的办法

http://xueshu.baidu.com/s?wd=paperuri:(3f2b4c4639032662a171f11d7713183a)&filter=sc_long_sign&sc_ks_para=q%3DMigration+of+epidural+canula&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8&sc_us=2910462810203157268