<dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>1.3.0</version>
</dependency>

<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.29</version>
    </dependency>

-- create table `account`
# DROP TABLE `account` IF EXISTS
CREATE TABLE `account` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(20) NOT NULL,
 `money` double DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
INSERT INTO `account` VALUES ('1', 'aaa', '1000');
INSERT INTO `account` VALUES ('2', 'bbb', '1000');
INSERT INTO `account` VALUES ('3', 'ccc', '1000');

spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
mybatis.mapper-locations=classpath*:mybatis/*Mapper.xml
mybatis.type-aliases-package=com.forezp.entity

public class Account {
  private int id ;
  private String name ;
  private double money;

  getter..
  setter..

 }

public interface AccountMapper2 {
  int update( @Param("money") double money, @Param("id") int id);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.forezp.dao.AccountMapper2">


  <update id="update">
    UPDATE account set money=#{money} WHERE id=#{id}
  </update>
</mapper>

@Service
public class AccountService2 {

  @Autowired
  AccountMapper2 accountMapper2;

  @Transactional
  public void transfer() throws RuntimeException{
    accountMapper2.update(90,1);//用户1减10块 用户2加10块
    int i=1/0;
    accountMapper2.update(110,2);
  }
}