6.查询

查询

//查询
    @Test
    void findByIdTest(){
        User user = userMapper.selectById(1);
        System.out.println(user);
    }
    
    //批量查询
    @Test
    void findTest(){
        List<User> users = userMapper.selectBatchIds(Arrays.asList(1, 2, 3, 4));
        users.forEach(System.out::println);
        //SELECT id,name,age,email,version,create_time,update_time FROM user WHERE id IN ( ? , ? , ? , ? )
    }

    //条件查询（map）
    @Test
    void findTestByMap(){
        Map<String, Object> map = new HashMap<>();
        map.put("name","刘波");
        List<User> users = userMapper.selectByMap(map);
        users.forEach(System.out::println);
    }