diff --git a/api/app/Http/Controllers/AdminController.php b/api/app/Http/Controllers/AdminController.php
index 4664b54..de4ca7a 100644
--- a/api/app/Http/Controllers/AdminController.php
+++ b/api/app/Http/Controllers/AdminController.php
@@ -62,7 +62,7 @@ class AdminController extends Controller
       DB::raw('admins.admin_auth_group as admin_auth_group'),
       DB::raw('admins.initial_password as initial_password'),
       DB::raw('admin_accounts.account as account'),
-      DB::raw('admin_auth_groups.name as admin_auth_group_name')
+      DB::raw("IFNULL(admin_auth_groups.name,'') as admin_auth_group_name")
     ])
       ->leftJoin('admin_accounts', function (JoinClause $join) {
         $join->on('admin_accounts.admin', '=', 'admins.id')
@@ -104,7 +104,7 @@ class AdminController extends Controller
       DB::raw('admins.admin_auth_group as admin_auth_group'),
       DB::raw('admins.initial_password as initial_password'),
       DB::raw('admin_accounts.account as account'),
-      DB::raw('admin_auth_groups.name as admin_auth_group_name')
+      DB::raw("IFNULL(admin_auth_groups.name,'') as admin_auth_group_name")
     ])
       ->leftJoin('admin_accounts', function (JoinClause $join) {
         $join->on('admin_accounts.admin', '=', 'admins.id')
@@ -147,7 +147,7 @@ class AdminController extends Controller
       DB::raw('admins.admin_auth_group as admin_auth_group'),
       DB::raw('admins.initial_password as initial_password'),
       DB::raw('admin_accounts.account as account'),
-      DB::raw('admin_auth_groups.name as admin_auth_group_name')
+      DB::raw("IFNULL(admin_auth_groups.name,'') as admin_auth_group_name")
     ])
       ->leftJoin('admin_accounts', function (JoinClause $join) {
         $join->on('admin_accounts.admin', '=', 'admins.id')