add

server/app/Http/Controllers/Api/V1/InteractionController.php

@@ -460,7 +460,9 @@ class InteractionController extends Controller
         if ($dream->user_id != $login_user_id) return $this->error(ErrorCode::NOT_ROOT);
         $interaction = InteractionInfo::find($interaction_id);
         if (empty($interaction)) return $this->error(ErrorCode::INTERACTION_NOT_EXIST);
-        $interaction->black_list = $user_id.',';
+        $black_list = '';
+        $black_list .= $user_id.',';
+        $interaction->black_list =$black_list;
         $ok = $interaction->save();
         if ($ok) return $this->api('');
         return $this->error(ErrorCode::OPERATION_FAILED);