详情代码看这里:https://github.com/iiYii/getyii/commit/b8315d083d5d07969ac163205bf1452216246666
并且已经开发一个扩展了,欢迎大家使用,扩展地址:https://github.com/yiier/yii2-backup
来源:http://www.getyii.com/topic/38