目标关联知识点数据查询优化--引入Map减少数据库查询次数

src/main/java/com/teaching/backend/model/entity/courses/ObjectiveContentKnow.java

@@ -45,7 +45,7 @@ public class ObjectiveContentKnow implements Serializable {
      * 关联的知识点
      */
 //    private String know;
-    private Integer knowId;
+    private Long knowId;
 
 
 }

src/main/java/com/teaching/backend/service/impl/courses/ObjectiveContentKnowServiceImpl.java

@@ -20,6 +20,7 @@ import com.teaching.backend.model.vo.knowtmp.KnowTmpVO;
 import com.teaching.backend.service.courses.IObjectiveContentKnowService;
 import com.teaching.backend.utils.CourseCode;
 import lombok.extern.slf4j.Slf4j;
+import org.neo4j.driver.internal.value.StringValue;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -30,6 +31,7 @@ import java.math.RoundingMode;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 /**
@@ -97,12 +99,19 @@ public class ObjectiveContentKnowServiceImpl extends ServiceImpl<ObjectiveConten
         ObjectiveContentKnowVO objectiveContentKnowVO = new ObjectiveContentKnowVO();
 
         // 根据传入的目标内容ID找到课程ID和总学时
-        String objectiveID = objectiveContentsMapper.selectOne(new LambdaQueryWrapper<ObjectiveContents>()
+        String objectiveID = objectiveContentsMapper.selectById(objectiveContentId).getObjectiveId();
-                .eq(ObjectiveContents::getId, objectiveContentId)).getObjectiveId();
+        CourseObjectives courseObjective = courseObjectivesMapper.selectOne(new LambdaQueryWrapper<CourseObjectives>()
-        String pid = courseObjectivesMapper.selectOne(new LambdaQueryWrapper<CourseObjectives>()
+                .eq(CourseObjectives::getId, objectiveID));
-                .eq(CourseObjectives::getId, objectiveID)).getPid();
+        String pid = courseObjective.getPid();
-        String courseId = courseObjectivesMapper.selectOne(new LambdaQueryWrapper<CourseObjectives>()
+        //当前内容属于总目标类型的
-                .eq(CourseObjectives::getId, pid)).getCourseId();
+        String courseId;
+        if(pid.equals(String.valueOf(CourseCode.CONTENT_BELONGS_TO_TOTAL_OBJECTIVE.getValue()))){
+            courseId = courseObjective.getCourseId();
+        }
+        else {
+            courseId = courseObjectivesMapper.selectOne(new LambdaQueryWrapper<CourseObjectives>()
+                    .eq(CourseObjectives::getId, pid)).getCourseId();
+        }
         Integer classhours = coursesMapper.selectById(courseId).getClasshours();
 
         // 获取当前目标内容下关联的知识点数据
@@ -127,22 +136,35 @@ public class ObjectiveContentKnowServiceImpl extends ServiceImpl<ObjectiveConten
     }
 
     // 创建ObjectiveContentKnowVO对象，并计算知识点数量、总时间和关联的知识点部分数据
-    // TODO 查询知识点的数据 有优化空间！！！
     private ObjectiveContentKnowVO createObjectiveContentKnowVO(String objectiveOrContentId, List<ObjectiveContentKnow> objectiveContentKnows) {
         ObjectiveContentKnowVO vo = new ObjectiveContentKnowVO();
         vo.setObjectiveOrContent(objectiveOrContentId);
         vo.setKnowsNumber(objectiveContentKnows.size());
 
-        // 计算知识点的总时间，并收集关联的知识点部分数据
+        // 提取所有的 Know IDs
+        List<Long> knowIds = objectiveContentKnows.stream()
+                .map(ObjectiveContentKnow::getKnowId)
+                .collect(Collectors.toList());
+
+        // 一次性查询所有需要的 Knowtmp 数据
+        List<Knowtmp> knows = knowtmpMapper.selectList(new LambdaQueryWrapper<Knowtmp>()
+                .in(Knowtmp::getId, knowIds));
+
+        // 使用 Map 来存储 Knowtmp 数据，以便快速查找
+        Map<Long, Knowtmp> knowMap = knows.stream()
+                .collect(Collectors.toMap(Knowtmp::getId, know -> know));
+
         Double knowsTime = 0.0;
         List<KnowTmpVO> knowTmpVOList = new ArrayList<>();
 
         for (ObjectiveContentKnow contentKnow : objectiveContentKnows) {
-            Knowtmp know = knowtmpMapper.selectOne(new LambdaQueryWrapper<Knowtmp>()
+            Knowtmp know = knowMap.get(contentKnow.getKnowId());
-                    .eq(Knowtmp::getId, contentKnow.getKnowId()));
             if (know == null) {
-                throw new BusinessException(ErrorCode.KNOW_NOT_EXIT);
+                log.warn("知识点不存在，id：{}", contentKnow.getKnowId());
+                // throw new BusinessException(ErrorCode.KNOW_NOT_EXIT);
+                continue; // 知识点不存在时跳过
             }
+
             knowsTime += know.getHour();
 
             // 将当前知识点数据添加到knowTmpVOList中
@@ -158,6 +180,7 @@ public class ObjectiveContentKnowServiceImpl extends ServiceImpl<ObjectiveConten
         return vo;
     }
 
+
     // 计算知识点学时占总学时的比例，并返回百分比形式的结果
     private Double calculatePercentage(Double knowsTime, Integer classhours) {
         if (classhours == null || classhours == 0) {

src/main/java/com/teaching/backend/utils/CourseCode.java

@@ -12,7 +12,7 @@ public enum CourseCode {
     TOTAL_OBJECTIVE_TYPE(0, "课程总目标"),
 
     TOTAL_OBJECTIVE_HAS_NO_CHILD(0, "课程总目标下面没有分项目标"),
-    Total_EXIT(0, "课程总目标"),
+    CONTENT_BELONGS_TO_TOTAL_OBJECTIVE(0, "该内容属于总目标"),
     COURSE_UPDATING(1, "课程正在修改中");