diff --git a/src/main/java/com/teaching/backend/mapper/umsAdmin/UmsUserMapper.java b/src/main/java/com/teaching/backend/mapper/umsAdmin/UmsUserMapper.java
index 7f422de..8ce099d 100644
--- a/src/main/java/com/teaching/backend/mapper/umsAdmin/UmsUserMapper.java
+++ b/src/main/java/com/teaching/backend/mapper/umsAdmin/UmsUserMapper.java
@@ -1,7 +1,6 @@
 package com.teaching.backend.mapper.umsAdmin;
 
 import com.baomidou.mybatisplus.core.mapper.BaseMapper;
-import com.teaching.backend.model.entity.courses.StudentCourses;
 import com.teaching.backend.model.entity.umsAdmin.UmsRole;
 import com.teaching.backend.model.entity.umsAdmin.UmsTeacher;
 import com.teaching.backend.model.entity.umsAdmin.UmsUser;
@@ -19,5 +18,5 @@ public interface UmsUserMapper extends BaseMapper<UmsUser> {
 
     UmsStudentVO getByIdStudent(String id);
 
-    String getbyIdRoleId(String userId);
+    String getByIdRoleId(String userId);
 }
diff --git a/src/main/java/com/teaching/backend/service/impl/courses/CoursesServiceImpl.java b/src/main/java/com/teaching/backend/service/impl/courses/CoursesServiceImpl.java
index 0056187..24f8d03 100644
--- a/src/main/java/com/teaching/backend/service/impl/courses/CoursesServiceImpl.java
+++ b/src/main/java/com/teaching/backend/service/impl/courses/CoursesServiceImpl.java
@@ -361,6 +361,7 @@ public class CoursesServiceImpl extends ServiceImpl<CoursesMapper, Courses> impl
     @Override
     public List<PersonalCenterStudentListVO> queryStudentList(String userId) {
         LinkedHashSet<UmsStudentManage> umsStudentManageList = queryTeacherByStudentList(userId);
+        System.out.println("1111111"+umsStudentManageList);
         List<PersonalCenterStudentListVO> personalCenterStudentListVOList = new ArrayList<>();
         PersonalCenterStudentListVO personalCenterStudentListVO = null;
         for (UmsStudentManage umsStudentManage : umsStudentManageList) {
@@ -375,7 +376,7 @@ public class CoursesServiceImpl extends ServiceImpl<CoursesMapper, Courses> impl
 
     @Override
     public LinkedHashSet<UmsStudentManage> queryTeacherByStudentList(String userId) {
-        String roleId = umsUserMapper.getbyIdRoleId(userId);
+        String roleId = umsUserMapper.getByIdRoleId(userId);
         CourseQuery courseQuery = new CourseQuery();
         courseQuery.setUserId(userId);
         LinkedHashSet<UmsStudentManage> umsStudentManageList = new LinkedHashSet<>();
@@ -388,13 +389,15 @@ public class CoursesServiceImpl extends ServiceImpl<CoursesMapper, Courses> impl
                 List<CourseLearningRecord> courseLearningRecordList = new ArrayList<>();
                 for (StudentCourses studentUsername : studentUsernames) {
                     CourseLearningRecord courseLearningRecord = courseLearningRecordMapper.selectNewRecord(String.valueOf(studentUsername.getStudent()));
-                    courseLearningRecordList.add(courseLearningRecord);
-                }
-                courseLearningRecordList = courseLearningRecordList.stream().sorted(Comparator.comparing(CourseLearningRecord::getTimes).reversed()).collect(Collectors.toList());
-                for (CourseLearningRecord courseLearningRecord : courseLearningRecordList) {
-                    UmsStudentManage umsStudentManage = umsStudentManageMapper.queryStudent(courseLearningRecord.getUserId());
-                    umsStudentManageList.add(umsStudentManage);
+                    if (courseLearningRecord != null){
+                        courseLearningRecordList.add(courseLearningRecord);
+                    }
                 }
+                    courseLearningRecordList = courseLearningRecordList.stream().sorted(Comparator.comparing(CourseLearningRecord::getTimes).reversed()).collect(Collectors.toList());
+                    for (CourseLearningRecord courseLearningRecord : courseLearningRecordList) {
+                        UmsStudentManage umsStudentManage = umsStudentManageMapper.queryStudent(courseLearningRecord.getUserId());
+                        umsStudentManageList.add(umsStudentManage);
+                    }
             }
             return umsStudentManageList;
         }
diff --git a/src/main/java/com/teaching/backend/service/impl/favour/SeCourseFavourServiceImpl.java b/src/main/java/com/teaching/backend/service/impl/favour/SeCourseFavourServiceImpl.java
index a260644..5cac41a 100644
--- a/src/main/java/com/teaching/backend/service/impl/favour/SeCourseFavourServiceImpl.java
+++ b/src/main/java/com/teaching/backend/service/impl/favour/SeCourseFavourServiceImpl.java
@@ -16,9 +16,6 @@ import com.teaching.backend.mapper.favour.SeCourseFavourMapper;
 import com.teaching.backend.mapper.umsAdmin.UmsUserMapper;
 import com.teaching.backend.model.entity.courses.Courses;
 import com.teaching.backend.model.entity.favour.SeCourseFavour;
-import com.teaching.backend.model.entity.favour.SeKnowFavour;
-import com.teaching.backend.model.entity.favour.SeResourceFavour;
-import com.teaching.backend.model.entity.umsAdmin.UmsUser;
 import com.teaching.backend.model.vo.courses.CoursesVO;
 import com.teaching.backend.model.vo.favour.CourseFavourDetailVO;
 import com.teaching.backend.service.courses.ICoursesService;
@@ -157,7 +154,7 @@ public class SeCourseFavourServiceImpl extends ServiceImpl<SeCourseFavourMapper,
 
     @Override
     public List<CoursesVO> queryNewCollect(String userId) {
-        String roleId = umsUserMapper.getbyIdRoleId(userId);
+        String roleId = umsUserMapper.getByIdRoleId(userId);
         List<Courses> coursesList = new ArrayList<>();
         if (roleId.equals("1")){
             //老师
diff --git a/src/main/java/com/teaching/backend/service/impl/records/CourseLearningRecordServiceImpl.java b/src/main/java/com/teaching/backend/service/impl/records/CourseLearningRecordServiceImpl.java
index 4c9eae5..fb3e253 100644
--- a/src/main/java/com/teaching/backend/service/impl/records/CourseLearningRecordServiceImpl.java
+++ b/src/main/java/com/teaching/backend/service/impl/records/CourseLearningRecordServiceImpl.java
@@ -123,7 +123,7 @@ public class CourseLearningRecordServiceImpl extends ServiceImpl<CourseLearningR
 
     @Override
     public List<CoursesVO> queryCourseList(String userId) {
-        String roleId = umsUserMapper.getbyIdRoleId(userId);
+        String roleId = umsUserMapper.getByIdRoleId(userId);
         List<Courses> coursesList = new ArrayList<>();
         if (roleId.equals("1")){
             List<String> courseIds = courseLearningRecordMapper.selectMaxNumber();
@@ -148,7 +148,7 @@ public class CourseLearningRecordServiceImpl extends ServiceImpl<CourseLearningR
 
     @Override
     public List<CoursesVO> queryrecommendCourses(String userId) {
-        String roleId = umsUserMapper.getbyIdRoleId(userId);
+        String roleId = umsUserMapper.getByIdRoleId(userId);
 
         if (roleId.equals("1")) {
 
diff --git a/src/main/java/com/teaching/backend/service/impl/records/KnowledgeLearningRecordServiceImpl.java b/src/main/java/com/teaching/backend/service/impl/records/KnowledgeLearningRecordServiceImpl.java
index cfe8d3e..c392c53 100644
--- a/src/main/java/com/teaching/backend/service/impl/records/KnowledgeLearningRecordServiceImpl.java
+++ b/src/main/java/com/teaching/backend/service/impl/records/KnowledgeLearningRecordServiceImpl.java
@@ -12,18 +12,12 @@ import com.teaching.backend.mapper.umsAdmin.UmsUserMapper;
 
 import com.teaching.backend.model.entity.KnowGraph.KnowledgeLearningNumber;
 
-import com.teaching.backend.model.entity.courses.CourseLearningNumber;
-
-import com.teaching.backend.model.entity.courses.Courses;
 import com.teaching.backend.model.entity.knowtmp.Knowtmp;
 import com.teaching.backend.model.entity.records.KnowledgeLearningRecord;
 
-import com.teaching.backend.model.vo.courses.CoursesVO;
 import com.teaching.backend.model.vo.knowGraph.KnowVO;
 import com.teaching.backend.model.vo.records.KnowledgeLearningRecordVo;
 
-import com.teaching.backend.service.Know.KnowService;
-import com.teaching.backend.service.impl.courses.CourseLearningNumberServiceImpl;
 import com.teaching.backend.service.impl.knowledge.KnowledgeLearningNumberServiceImpl;
 import com.teaching.backend.service.knowtmp.KnowtmpService;
 import com.teaching.backend.service.records.IKnowledgeLearningRecordService;
@@ -141,7 +135,7 @@ public class KnowledgeLearningRecordServiceImpl extends ServiceImpl<KnowledgeLea
 
     @Override
     public List<KnowVO> queryMaxKnowledge(String userId) {
-        String roleId = umsUserMapper.getbyIdRoleId(userId);
+        String roleId = umsUserMapper.getByIdRoleId(userId);
         List<KnowVO> coursesList = new ArrayList<>();
         KnowVO knowVO = null;
         if (roleId.equals("1")){
diff --git a/src/main/resources/mapper/UmsUserMapper.xml b/src/main/resources/mapper/UmsUserMapper.xml
index 5b56d4a..6ea4599 100644
--- a/src/main/resources/mapper/UmsUserMapper.xml
+++ b/src/main/resources/mapper/UmsUserMapper.xml
@@ -76,7 +76,7 @@
         WHERE
             s.user_id = #{id}
     </select>
-    <select id="getbyIdRoleId" parameterType="java.lang.String" resultType="java.lang.String">
+    <select id="getByIdRoleId" parameterType="java.lang.String" resultType="java.lang.String">
         SELECT
             us.role_id roleId
         FROM