__init__.py 文件源码

def downgrade(directory=None, revision='-1', sql=False, tag=None, x_arg=None):
    """Revert to a previous version"""
    config = current_app.extensions['migrate'].migrate.get_config(directory,
                                                                  x_arg=x_arg)
    if sql and revision == '-1':
        revision = 'head:-1'
    command.downgrade(config, revision, sql=sql, tag=tag)