参考：
https://blog.csdn.net/csdnxingyuntian/article/details/57081233
https://www.cnblogs.com/huanongying/p/7021555.html
https://segmentfault.com/a/1190000006158186
Mysql ACID与隔离级别
原文：https://www.cnblogs.com/free-wings/p/9726147.html
