删除学生修改

mec-biz/src/main/java/com/ym/mec/biz/service/impl/ClassGroupStudentMapperServiceImpl.java

@@ -56,7 +56,7 @@ public class ClassGroupStudentMapperServiceImpl extends BaseServiceImpl<Long, Cl
         classStudentMapper.setStatus(ClassGroupStudentStatusEnum.QUIT);
         update(classStudentMapper);
         StudentRegistration student = studentRegistrationService.findStudentByClassGroupIdAndUserId(userId, classGroupId);
-        student.setClassGroupId(null);
+        student.setClassGroupId(0);
         studentRegistrationService.update(student);
 
         //2、班级人数调整