Innodb中的事务隔离级别和锁的关系

https://tech.meituan.com/innodb-lock.html

https://www.jianshu.com/p/4e3edbedb9a8

15.2.10 . InnoDB事务模型和锁定

http://www.iteedu.com/database/mysql/mysqlmanualcn/storage-engines/innodb-transaction-model.php