（java）使用Mybatis-Plus中执行sql的一些常用语句

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class TestSpringMP {
    @Autowired
    private UserMapper userMapper;


    
    @Test
    public void testSelectList() {
        List users = this.userMapper.selectList(null);
           for (User user : users)
            System.out.println(user);
    }

    
    @Test
    public void testSelectById() {
        User user = userMapper.selectById(7L);
        System.out.println(user);
    }
    
    @Test
    public void testSelectByIds() {
        List users = userMapper.selectBatchIds(Arrays.asList(1L, 2L));
        for (User user : users) {
            System.out.println(user);
        }

    }
    
    @Test
    public void testSelectByConditions() {
        User user = new User();
        user.setAge(20);
        QueryWrapper wrapper = new QueryWrapper<>(user);
        User user1 = userMapper.selectOne(wrapper);
        System.out.println(user1);
    }

    
    @Test
    public void testSelectCount() {
//        QueryWrapper