How to use sqlalchemy-migrate with declarative db model

I try add to some table new column, how its described in documentation for sqlalchemy-migrate< like:

col = Column('col1', String, default='foobar')
col.create(table, populate_default=True)

But I get error, i think its because i use declarative models, how i can us开发者_开发问答e migrations?

def upgrade(migrate_engine):
    Base.metadata.bind = migrate_engine
    col = Column('col1', String, default='foobar')
    col.create(table, populate_default=True)`

worked for me.