Insight mysql-connector connection 部分实现

疑问：和事务有关的操作，setTransactionIsolation ，setAutoCommit，commit做了什么处理?

setAutoCommit 和start transaction 有什么区别？

怎样实现读事务控制？

...

Insight mysql-connector Connection实现ConnectionImpl。

...

直接上结论：

a. setTransactionIsolation 按照隔离级别，分别执行sql command:

"SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED";

"SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED";

"SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ";

"SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE";

b.setAutoCommit 执行sql command:

autoCommitFlag ? "SET autocommit=1" : "SET autocommit=0"；

同start transaction 功能。

按照接口描述：If a connection is in auto-commit mode, than all its SQL statements will be executed and committed as individual transactions. 

Otherwise, its SQL statements are grouped into transactions that are terminated by either commit() or rollback().