mysql 事务

--        start transaction 开启事务
--        Rollback 回滚事务,即撤销指定的sql语句(只能回退insert delete update语句)，回滚到上一次commit的位置
--        Commit 提交事务，提交未存储的事务
-- 
--        savepoint 保留点 ，事务处理中设置的临时占位符 你可以对它发布回退(与整个事务回退不同)     

新建一张表

mysql> create table account(id int,name varchar(20),balance double);
Query OK, 0 rows affected (0.07 sec)

mysql> insert into account values(1,'cunzhang',8000);
Query OK, 1 row affected (0.01 sec)

mysql> insert into account values(2,'zhengwen',8000);
Query OK, 1 row affected (0.01 sec)

mysql> select * from account;
+------+----------+---------+
| id   | name     | balance |
+------+----------+---------+
|    1 | cunzhang |    8000 |
|    2 | zhengwen |    8000 |
+------+----------+---------+

开始事务
mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)


-- id=1 balance-5000

mysql> update account set balance = balance-5000 where id =1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from account;
+------+----------+---------+
| id   | name     | balance |
+------+----------+---------+
|    1 | cunzhang |    3000 |
|    2 | zhengwen |    8000 |
+------+----------+---------+
2 rows in set (0.00 sec)

回滚事务   
mysql> rollback;
Query OK, 0 rows affected (0.01 sec)

mysql> select * from account;
+------+----------+---------+
| id   | name     | balance |
+------+----------+---------+
|    1 | cunzhang |    8000 |
|    2 | zhengwen |    8000 |
+------+----------+---------+

 

--   id=2  balance+5000

mysql> update account set balance = balance+5000 where id =2;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from account;
+------+----------+---------+
| id   | name     | balance |
+------+----------+---------+
|    1 | cunzhang |    3000 |
|    2 | zhengwen |   13000 |
+------+----------+---------+
2 rows in set (0.00 sec)




结束事务

mysql> commit;
Query OK, 0 rows affected (0.02 sec)

mysql> select * from account;
+------+----------+---------+
| id   | name     | balance |
+------+----------+---------+
|    1 | cunzhang |    3000 |
|    2 | zhengwen |   13000 |
+------+----------+---------+