学成在线,查询课程计划
查询课程计划
界面原型
当我们新增/修改完课程基本信息后,将自动进入课程计划编辑界面,课程计划分为大章节和小章节
数据模型
teach_plan表: 一个课程可以关联多个课程计划,课程计划分为章节(grade为1)和小节(grade为2)两种,节的parentid为章的Id,章的parentid为0
teachplan_media表: 一个课程计划小节只能绑定一个媒资文件,但不同的课程计划小节可以绑定同一个媒资文件
响应数据模型类
根据课程Id查询课程关联的所有课程计划
GET /teachplan/22/tree-nodes
定义查询课程计划接口的响应模型类,该类主要有章基本信息,章下的所有小节信息,小节关联的媒资信息三部分组成
@Data
public class TeachplanDto extends Teachplan {
// 课程计划关联的媒资信息,章节没有关联的媒资信息
private TeachplanMedia teachplanMedia;
// 章节下的小节信息
private List<TeachplanDto> teachPlanTreeNodes;
}
// 响应结果为一个数组,数组中的元素就是要查询的课程关联的章节
[
{
// 章节的基本信息
"changeDate": null,
"courseId": 74,
"cousePubId": null,
"createDate": null,
"endTime": null,
"grade": "2",
"isPreview": "0",
"mediaType": null,
"orderby": 1,
"parentid": 0,
"pname": "第1章基础知识",
"startTime": null,
"status": null,
"id": 113,
// 章节下的所有小节信息
"teachPlanTreeNodes": [
{
// 小节的基本信息
"changeDate": null,
"courseId": 74,
"cousePubId": null,
"createDate": null,
"endTime": null,
"grade": "3",
"isPreview": "1",
"mediaType": "001002",
"orderby": 1,
"parentid": 113,
"pname": "第1节项目概述",
"startTime": null,
"status": null,
"id": 115,
"teachPlanTreeNodes": null,
// 小节会关联媒资信息,如视频文档等
"teachplanMedia": {
"courseId": 74,
"coursePubId": null,
"mediaFilename": "2.avi",
"mediaId": 41,
"teachplanId": 115,
"id": null
}
}],
// 章节不关联媒资信息
"teachplanMedia": null
},
// 其他章节信息
]
业务开发
第一步: 编写接口根据课程Id查询课程关联的所有课程计划
@Slf4j
@RestController
@Api(value = "课程计划编辑接口", tags = "课程计划编辑接口")
public class TeachplanController {
@Autowired
private TeachplanService teachplanService;
@ApiOperation("查询课程计划树形结构")
@GetMapping("/teachplan/{courseId}/tree-nodes")
public List<TeachplanDto> getTreeNodes(@PathVariable Long courseId) {
return teachplanService.findTeachplanTree(courseId);
}
}
第二步: 编写Mapper接口及SQL映射文件,自定义SQL语句按照响应结果手动配置查询结果的映射,最后组成一个树形结构返回
- 如果章节下没有小节,此时也需要显示章节,所以通过teachplan表进行左连接,左边是一级分类,右边是二级分类
- 当课程计划还没有关联媒资文件时,
teachplan_media表中对应的记录为空,所以需要teachplan和teachplan_media左连接
public interface TeachplanMapper extends BaseMapper<Teachplan> {
// 根据课程Id去数据库中查询课程关联的课程计划
List<TeachplanDto> selectTreeNodes(Long courseId);
}
<resultMap id="treeNodeResultMap" type="com.xuecheng.content.model.dto.TeachplanDto">
<id column="p_id" property="id">id>
<result column="p_pname" property="pname">result>
<result column="p_parentid" property="parentid">result>
<result column="p_grade" property="grade">result>
<result column="p_mediaType" property="mediaType">result>
<result column="p_startTime" property="startTime"/>
<result column="p_endTime" property="endTime">result>
<result column="p_orderby" property="orderby">result>
<result column="p_courseId" property="courseId">result>
<result column="p_coursePubId" property="coursePubId">result>
<collection property="teachPlanTreeNodes" ofType="com.xuecheng.content.model.dto.TeachplanDto">
<id column="c_id" property="id">id>
<result column="c_pname" property="pname">result>
<result column="c_parentid" property="parentid">result>
<result column="c_grade" property="grade">result>
<result column="c_mediaType" property="mediaType">result>
<result column="c_startTime" property="startTime"/>
<result column="c_endTime" property="endTime">result>
<result column="c_orderby" property="orderby">result>
<result column="c_courseId" property="courseId">result>
<result column="c_coursePubId" property="coursePubId">result>
<association property="teachplanMedia" javaType="com.xuecheng.content.model.po.TeachplanMedia">
<result column="teachplanMeidaId" property="id">result>
<result column="mediaFilename" property="mediaFilename">result>
<result column="mediaId" property="mediaId">result>
<result column="c_id" property="teachplanId" />
<result column="c_courseId" property="courseId" />
<result column="c_coursePubId" property="coursePubId" />
association>
collection>
resultMap>
<select id="selectTreeNodes" resultMap="treeNodeResultMap">
SELECT p.id p_id,
p.pname p_pname,
p.parentid p_parentid,
p.grade p_grade,
p.media_type p_mediaType,
p.start_time p_stratTime,
p.end_time p_endTime,
p.orderby p_orderby,
p.course_id p_courseId,
p.course_pub_id p_coursePubId,
c.id c_id,
c.pname c_pname,
c.parentid c_parentid,
c.grade c_grade,
c.media_type c_mediaType,
c.start_time c_stratTime,
c.end_time c_endTime,
c.orderby c_orderby,
c.course_id c_courseId,
c.course_pub_id c_coursePubId,
tm.media_fileName mediaFilename,
tm.id teachplanMeidaId,
tm.media_id mediaId
FROM teachplan p
LEFT JOIN teachplan c ON c.parentid = p.id
LEFT JOIN teachplan_media tm ON tm.teachplan_id = c.id
WHERE p.parentid = '0' AND p.course_id = #{value}
ORDER BY p.orderby, c.orderby
select>
第三步: 编写Service接口及其实现类
public interface TeachplanService {
List<TeachplanDto> findTeachplanTree(Long courseId);
}
@Slf4j
@Service
public class TeachplanServiceImpl implements TeachplanService {
@Autowired
private TeachplanMapper teachplanMapper;
@Override
public List<TeachplanDto> findTeachplanTree(Long courseId) {
return teachplanMapper.selectTreeNodes(courseId);
}
}