Thanks for the link. I know about DynamicQuery, but never tested it so far. AFAIK, it is ORM-independent, so it must work with our own IQueryable implementation.

Custom LINQ translators (and LINQ preprocessors) in DO4 are designed to solve a bit different problem:

• Translators add support for new features you can use in queries;

• Preprocessors can transform the original query to something completely different before it gets compiled (e.g. to add security checks).

But in both cases you can use such tools as DynamicQuery to solve the problem.

Btw, I checked up the links there further, and found few more nice things:

• PredicateBuilder: http://www.albahari.com/nutshell/predicatebuilder.aspx

• AsExpandable(): http://www.albahari.com/nutshell/linqkit.aspx

AsExpandable() is based on original post @ http://tomasp.net/ blog. I'm reading it during last few months - the author makes really great posts, the content is mainly related to functional programming on .NET.