diff --git a/src/main/java/com/guo/learningprogresstracker/service/impl/TasksServiceImpl.java b/src/main/java/com/guo/learningprogresstracker/service/impl/TasksServiceImpl.java
index f21c398..c44b4a1 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/impl/TasksServiceImpl.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/impl/TasksServiceImpl.java
@@ -71,7 +71,17 @@ public class TasksServiceImpl extends ServiceImpl<TasksMapper, TaskEntity>
     @Override
     public void updateTask(String taskId, TaskRequest updatedTask) {
         TaskEntity taskEntity = TaskConvert.MAPPER.taskRequestToTaskEntity(updatedTask);
-        this.updateById(taskEntity);
+        int id;
+        try {
+            id = Integer.parseInt(taskId);
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException("任务ID格式错误: " + taskId);
+        }
+        taskEntity.setId(id);
+        boolean updated = this.updateById(taskEntity);
+        if (!updated) {
+            throw new IllegalArgumentException("任务不存在或更新失败: " + taskId);
+        }
 
     }
 
@@ -86,4 +96,3 @@ public class TasksServiceImpl extends ServiceImpl<TasksMapper, TaskEntity>
 
 
 
-
diff --git a/src/main/resources/mapper/StudyReportsMapper.xml b/src/main/resources/mapper/StudyReportsMapper.xml
index 1d63e81..d199754 100644
--- a/src/main/resources/mapper/StudyReportsMapper.xml
+++ b/src/main/resources/mapper/StudyReportsMapper.xml
@@ -26,6 +26,8 @@
         from study_sessions ss
                  left join tasks t on ss.task_num = t.task_num and ss.session_state != 'ENDED' and ss.deleted = 0
         where t.deleted = 0
-          and t.task_num = ${task_num}
+          and t.task_num = #{task_num}
+        order by ss.last_modified_time desc, ss.created_time desc
+        limit 1
     </select>
 </mapper>