diff --git a/VOL.Business/Services/School/S_StudentService.cs b/VOL.Business/Services/School/S_StudentService.cs
index eb9d1bb..6396cd1 100644
--- a/VOL.Business/Services/School/S_StudentService.cs
+++ b/VOL.Business/Services/School/S_StudentService.cs
@@ -94,7 +94,8 @@ namespace VOL.Business.Services.School
 
 
             var query = from s in _studentRepository.DbContext.Set<S_Student>()
-                        join c in _studentRepository.DbContext.Set<S_Class>() on s.ClassId equals c.Id
+                        join c in _studentRepository.DbContext.Set<S_Class>() on s.ClassId equals c.Id into sc
+                        from c in sc.DefaultIfEmpty()
 
                         where s.SchoolCode.Equals(UserContext.Current.TenantId) && s.StudentStatus == StudentStatus.Normal && (!isTeacher || classIds.Contains(c.Id))
 
diff --git a/VOL.WebApi/Controllers/AI/AiAppController.cs b/VOL.WebApi/Controllers/AI/AiAppController.cs
index bb681fa..c8e6106 100644
--- a/VOL.WebApi/Controllers/AI/AiAppController.cs
+++ b/VOL.WebApi/Controllers/AI/AiAppController.cs
@@ -106,7 +106,7 @@ namespace VOL.WebApi.Controllers
         /// </summary>
         /// <returns></returns>
         [HttpGet(nameof(ItemTypeList))]
-        [ServiceFilter(typeof(ValidateDeviceFilter))]
+        [ServiceFilter(typeof(ValidateDeviceFilter))]  
         public async Task<List<Ai_ModeTypeModel>> ItemTypeList(Ai_Request paramDto)
         {
             return await _aiAppService.ItemTypeList();