select查询操作

@Test
public void testSelect(){
    User user = mapper.selectById(1L);
    System.out.println(user);
}
//User(id=1, name=two, age=101, email=saxon@qq.com, version=4, createTime=null, updateTime=Thu Jul 29 15:48:15 CST 2021)

@Test
public void testSelect1(){
    List<User> users = mapper.selectBatchIds(Arrays.asList(1, 2, 3));
    users.forEach(System.out::println);
}
//输出结果
User(id=1, name=two, age=101, email=saxon@qq.com, version=4, createTime=null, updateTime=Thu Jul 29 15:48:15 CST 2021)
User(id=2, name=Jack, age=20, email=test2@baomidou.com, version=1, createTime=null, updateTime=null)
User(id=3, name=Tom, age=28, email=test3@baomidou.com, version=1, createTime=null, updateTime=null)

//按条件查询
@Test
public void testSelect2(){
    HashMap<String, Object> map = new HashMap<>();
    map.put("name","two");
    List<User> users = mapper.selectByMap(map);
    users.forEach(System.out::println);
}
//User(id=1, name=two, age=101, email=saxon@qq.com, version=4, createTime=null, updateTime=Thu Jul 29 15:48:15 CST 2021)