Querying by Key in Google App Engine?

I need to get entity by user key that is setted as Id for User entity. Now I want to query all entities th开发者_运维百科at have same key that user has. How can I do that?

Okey, now I found solution myself:

Query query = pm.newQuery(Entity.class, "user == userParam");
            query.declareParameters("com.google.appengine.api.datastore.Key userParam");