使用springboot 配置了
@EnableTransactionManagement
@Transactional但是事务根本不起作用。
首先第一点：Spring的AOP事务管理默认是针对RunTimeException回滚，这个例外是unchecked exceptions。unchecked exception异常都是RuntimeException的子类。
如果遇到checked exceptions意外就不回滚。
如何改变默认规则：
1 让checked例外也回滚：在整个方法前加上 @Transactional(rollbackFor=Exception.class)
2 让unchecked例外不回滚： @Transactional(notRollbackFor=RunTimeException.class)
checked exceptions 其必须被 try{}catch语句块所捕获,或者在方法签名里通过throws子句声明.受检查的异常必须在编译时被捕捉处理。
unchecked exceptions 需要程序员自己分析代码决定是否捕获和处理,比如 空指针,被0除...
其次是第二点
查看数据库中，表的引擎方式。
1 查看mysql现在已提供什么存储引擎: show engines; 只有InnoDB是支持事务的
mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine | Support | Comment | Transactions | XA | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
| CSV | YES | CSV storage engine | NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
| InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
| ARCHIVE | YES | Archive storage engine | NO | NO | NO |
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
| FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
2 查看自己的表的引擎方式 show create table 表名;
或者 show table status from db_name where name='table_name';
mysql> show create table user;
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| user | CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`grade_id` bigint(20) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
mysql> show table status from test where name='user';
+------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |
+------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
| user | MyISAM | 10 | Dynamic | 1 | 20 | 20 | 281474976710655 | 2048 | 0 | 2 | 2018-04-27 21:50:12 | 2018-04-28 18:43:10 | NULL | utf8_general_ci | NULL | | |
+------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
可以看到 user表是MyISAM引擎创建的，不支持事务。
3 修改表为InnoDB引擎 alter table table_name engine=innodb;