spingboot的读提交事务不生效

Question

CREATE TABLE `users` (
  `name` varchar(200) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
  `sex` varchar(2) NOT NULL,
  `AGE` int(11) NOT NULL,
  `email` varchar(32) NOT NULL,
  `password` varchar(40) NOT NULL,
  `id` int(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`),
  UNIQUE KEY `name_unique` (`name`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=14 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci


INSERT INTO `dba6`.`users`(`name`, `sex`, `AGE`, `email`, `password`, `id`) VALUES ('张三', '男', 11, '[e-mail]', '112233', 1);

import com.example.mybatis_plus.entity.UsersEntity;
import com.example.mybatis_plus.mapper.UsersDao;
import com.example.mybatis_plus.service.UsersService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;


@Service("usersService")

public class UsersServiceImpl  implements UsersService {

    @Autowired
    private UsersDao usersDao;

    @Override
    @Transactional(rollbackFor = Exception.class,isolation = Isolation.READ_COMMITTED, propagation = Propagation.REQUIRES_NEW)
    public void updateUser() throws InterruptedException {

            System.out.println("开始执行了");
            UsersEntity usersEntity=usersDao.selectById(1);

            usersEntity.setName("李四");
            usersDao.updateById(usersEntity);

            Thread.sleep(20*000);


    }

    @Override
    @Transactional(rollbackFor = Exception.class,isolation = Isolation.READ_COMMITTED, propagation = Propagation.REQUIRES_NEW)
    public void getUser() throws InterruptedException {
        UsersEntity usersEntity = usersDao.selectById(1);
        System.out.println(usersEntity);

        Thread.sleep(60*1000);
        usersEntity = usersDao.selectById(1);
        System.out.println(usersEntity);
    }
}

1. 我先执行updateUser，再执行getUser。
2. 两者事务，都是读提交。
3. getUser第一次执行时，输出的name为张三
4. 但getUser第二次执行时，updateUser已经更新（20秒），而事务是读提交的，此时getUser在60秒后读取，应该是李四，但结果依旧为张三？？把事务替换为可重复读，也是这个效果

UsersEntity(name=张三, sex=男, age=11, email=[e-mail], password=112233, id=1)
开始执行了
UsersEntity(name=张三, sex=男, age=11, email=[e-mail], password=112233, id=1)

Answer 1

缓存问题,数据库应该已经改成李四了
一级缓存作用域是sqlsession级别的，同一个sqlsession中执行相同的sql查询（相同的sql和参数），第一次会去查询数据库并写到缓存中，第二次从一级缓存中取。