https://blog.csdn.net/zhangsheng_1992/article/details/52598396
https://blog.csdn.net/xiyangyang8110/article/details/52163106
https://blog.csdn.net/weixin_41147129/article/details/88892458
Sqlite—锁机制
原文：https://www.cnblogs.com/liuhaidon/p/12059080.html
