diff --git a/app/Services/OperationLogService.php b/app/Services/OperationLogService.php
index 2188b16..a627c52 100644
--- a/app/Services/OperationLogService.php
+++ b/app/Services/OperationLogService.php
@@ -18,7 +18,7 @@ class OperationLogService
             'user_name' => $user?->name ?? '',
             'message' => $message,
             'data_type' => $model ? $model::class : '',
-            'data_id' => $model?->id ?? '',
+            'data_id' => $model?->id ?? null,
             'type' => $type,
             'input_data' => $parms,
             'created_at' => now(),