Java的新项目学成在线笔记-day6(十)
作者:互联网
3.2.3 课程管理服务 3.2.3.1 Sql
课程计划是树型结构,采用表的自连接方式进行查询,sql语句如下:
SELECT
a.id one_id, a.pname one_pname, b.id two_id, b.pname two_pname, c.id three_id,
c.pname three_pname FROM
teachplan a
LEFT JOIN teachplan b
ON a.id = b.parentid
LEFT JOIN teachplan c
ON b.id = c.parentid WHERE a.parentid = '0'
AND a.courseid = '402885816243d2dd016243f24c030002' ORDER BY a.orderby,
b.orderby,
c.orderby
3.2.3.2 Dao
1) mapper接口
@Mapper public interface TeachplanMapper {
public TeachplanNode selectList(String courseId); }
2)mapper映射文件
<resultMap type="com.xuecheng.framework.domain.course.ext.TeachplanNode" id="teachplanMap" > <id property="id" column="one_id"/>
<result property="pname" column="one_name"/>
<collection property="children"
ofType="com.xuecheng.framework.domain.course.ext.TeachplanNode">
<id property="id" column="two_id"/>
<result property="pname" column="two_name"/>
<collection property="children" ofType="com.xuecheng.framework.domain.course.ext.TeachplanNode">
<id property="id" column="three_id"/>
<result property="pname" column="three_name"/>
</collection>
</collection>
</resultMap>
<select id="selectList" resultMap="teachplanMap" parameterType="java.lang.String" >
SELECT
a.id one_id,
a.pname one_name,
b.id two_id,
b.pname two_name,
c.id three_id,
c.pname three_name
FROM
teachplan a LEFT JOIN teachplan b
ON a.id = b.parentid
LEFT JOIN teachplan c
ON b.id = c.parentid
WHERE a.parentid = '0'
<if test="_parameter!=null and _parameter!=''">
and a.courseid=#{courseId}
</if>
ORDER BY a.orderby,
b.orderby,
c.orderby </select>
说明:针对输入参数为简单类型#{}中可以是任意类型,判断参数是否为空要用 _parameter(它属于mybatis的内 置参数)
3.4.3.3 Service
创建CourseService类,定义查询课程计划方法。
@Service public class CourseService {
@Autowired
TeachplanMapper teachplanMapper;
//查询课程计划
public TeachplanNode findTeachplanList(String courseId){
TeachplanNode teachplanNode = teachplanMapper.selectList(courseId);
return teachplanNode;
} }
3.4.3.4 Controller
@RestController @RequestMapping("/course") public class CourseController implements CourseControllerApi {
@Autowired
CourseService courseService;
//查询课程计划
@Override
@GetMapping("/teachplan/list/{courseId}")
public TeachplanNode findTeachplanList(String courseId) {
return courseService.findTeachplanList(courseId);
} }
3.4.3.5 测试
使用postman或swagger-ui测试查询接口。 Get 请求:http://localhost:31200/course/teachplan/list/402885816243d2dd016243f24c030002
标签:学成,Java,teachplan,day6,public,courseId,pname,parentid,id 来源: https://blog.csdn.net/czbkzmj/article/details/87936470