===Returning Results===
It is not possible to mix different types of expressions in a query result. The outermost expression of a query must either be a collection of updating or non-updating expressions. Generally there is no way to perform any updating queries and return a result at the same time , as you cannot access your own changes during a single query. Regarding database nodes, you can update your nodes within the first query and access modifications in subsequent queries.
But trying to modify and return a DOM node within the same snapshot is another story. As changes on DOM nodes are non-persistent, you cannot access them in a subsequent query. This is where the transform expression comes into play.