事务_事务隔离级别演示1与事务_事务隔离级别演示2

事务_事务隔离级别演示1

　　　　　　演示：　　

　　　　　　　　SET GLOBAL TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

　　　　　　　　#开启事务

　　　　　　　　　　START TRANSACTION;

　　　　　　　　#1.莫凡账户 - 500元

　　　　　　　　　 UPDATE accont SET balance = balance -500 WHERE NAME ='mofan';

　　　　　　　#2.王耀账户 + 500元

　　　　　　　　　　UPDATE accont SET balance = balance +500 WHERE NAME ='wangyao';　　　　　　　

#设置隔离级别
SET GLOBAL TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

#查询隔离级别
SELECT @@transaction_isolation;

#开启事务
START TRANSACTION;

#1.莫凡账户 - 500元
UPDATE accont SET balance = balance -500 WHERE NAME ='mofan';
#2.王耀账户 + 500元
UPDATE accont SET balance = balance +500 WHERE NAME ='wangyao';

#事务回滚
ROLLBACK;


#设置隔离级别
SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED;

#数据还原成1000
UPDATE accont SET balance = 1000;

#开启事务
START TRANSACTION;

#1.莫凡账户 - 500元
UPDATE accont SET balance = balance -500 WHERE NAME ='mofan';
#2.王耀账户 + 500元
UPDATE accont SET balance = balance +500 WHERE NAME ='wangyao';

#提交事务
COMMIT;

 

事务_事务隔离级别演示2　　　

　　　　

#设置隔离级别
SET GLOBAL TRANSACTION ISOLATION LEVEL REPEATABLE READ;

#数据还原成1000
UPDATE accont SET balance = 1000;

#开启事务
START TRANSACTION;

#1.莫凡账户 - 500元
UPDATE accont SET balance = balance -500 WHERE NAME ='mofan';
#2.王耀账户 + 500元
UPDATE accont SET balance = balance +500 WHERE NAME ='wangyao';

#提交事务
COMMIT;

#修改隔离级别
SET GLOBAL TRANSACTION ISOLATION LEVEL SERIALIZABLE;
#开启事务
START TRANSACTION;

#1.莫凡账户 - 500元
UPDATE accont SET balance = balance -500 WHERE NAME ='mofan';
#2.王耀账户 + 500元
UPDATE accont SET balance = balance +500 WHERE NAME ='wangyao';