diff --git a/pipeline_service/storage.py b/pipeline_service/storage.py
index 0dc4c8b..56e2c4f 100644
--- a/pipeline_service/storage.py
+++ b/pipeline_service/storage.py
@@ -206,10 +206,12 @@ async def list_tasks(tenant_id: str, pipeline_id: str = None, limit: int = 100)
     """List tasks for a tenant."""
     db, dbname = _get_db()
     async with db.sqlorContext(dbname) as sor:
-        filters = {'tenant_id': tenant_id}
         if pipeline_id:
-            filters['pipeline_id'] = pipeline_id
-        recs = await sor.R('pipeline_tasks', filters, sort='created_at desc')
+            sql = "SELECT * FROM pipeline_tasks WHERE tenant_id=${tenant_id}$ AND pipeline_id=${pipeline_id}$ ORDER BY created_at DESC"
+            recs = await sor.sqlExe(sql, {'tenant_id': tenant_id, 'pipeline_id': pipeline_id})
+        else:
+            sql = "SELECT * FROM pipeline_tasks WHERE tenant_id=${tenant_id}$ ORDER BY created_at DESC"
+            recs = await sor.sqlExe(sql, {'tenant_id': tenant_id})
         result = []
         for rec in (recs or [])[:limit]:
             if hasattr(rec, '__dict__'):