Spring Boot连表查询data为空

Question

求问，Spring Boot+mybatisplus连表查询，后端返回的data一直是null，不知道哪里错了
Controller

@RestController
@RequestMapping("/course")
public class CourseController {
    @GetMapping("/page")
    public Result findPage(
                           @RequestParam Integer pageNum,
                           @RequestParam Integer pageSize) {
        Page<Course> page = courseService.findPage(new Page<>(pageNum, pageSize));
        return Result.success(page);
    }
}

Service层

@Service
public class CourseServiceImpl extends ServiceImpl<CourseMapper, Course> implements ICourseService {
    @Resource
    private CourseMapper courseMapper;

    @Override
    public Page<Course> findPage(Page<Course> page) {
        return courseMapper.findPage(page);
    }
}

public interface ICourseService extends IService<Course> {
    Page<Course> findPage(Page<Course> page);
}

Mapper

public interface CourseMapper extends BaseMapper<Course> {
    Page<Course> findPage(Page<Course> page);
}

    <select id="findPage" resultType="com.example.springboot.entity.Course">
        select course.*,student.name as teacher  from course
        left join student
        on course.teacher_id = student.id
    </select>

调用后端接口返回
"code": "200",
"msg": "",
"data": null

Answer 1

可以远程给你调试