diff --git a/server/imserver/dbengine.cc b/server/imserver/dbengine.cc
index 1175025..85d95ff 100644
--- a/server/imserver/dbengine.cc
+++ b/server/imserver/dbengine.cc
@@ -162,12 +162,12 @@ void DBEngine::RefreshIdx()
     auto on_ok =
         [] (a8::XParams& param, const f8::DataSet* data_set)
         {
-            long long instance_id = param.sender.GetInt64() + 1;
+            long long instance_idx = param.sender.GetInt64();
             const std::vector<std::string>& row = (*data_set)[0];
             long long friend_apply_idx = a8::XValue(row[0]);
             long long event_idx = a8::XValue(row[1]);
-            DBEngine::Instance()->UpdateFriendApplyIdx(instance_id, friend_apply_idx);
-            DBEngine::Instance()->UpdateEventIdx(instance_id, event_idx);
+            DBEngine::Instance()->UpdateFriendApplyIdx(instance_idx, friend_apply_idx);
+            DBEngine::Instance()->UpdateEventIdx(instance_idx, event_idx);
         };
     auto on_error =
         [] (a8::XParams& param, int error_code, const std::string& error_msg)