Working on Datagrid interaction

src/myfasthtml/core/dbmanager.py

@@ -98,6 +98,8 @@ class DbObject:
     properties = {}
     if args:
       arg = args[0]
+      if arg is None:
+        return self
       if not isinstance(arg, (dict, SimpleNamespace)):
         raise ValueError("Only dict or Expando are allowed as argument")
       properties |= vars(arg) if isinstance(arg, SimpleNamespace) else arg