Silverlight的XML和数据库过滤：动态LINQ？有没有更好的办法？

I have a Silveright app that allows users to specify filters on a few different sets of persisted data. The persisted data can be XML or a relational database table. I'm using nHibernate for the database layer as I need to support different database options, Postgresql and MySQL at a minimum. The filter fields vary depending on which data set is being queried.I have a Silveright app that allows users to sp