mapping computed properties linq-to-sql actuall sql statements

i have combined additional functionality linq-to-sql classes things easier i arise applications. instance i have tangible ability retrieves active contracts list contracts. however i try ability lambda countenance whole query presumably throws an difference there sql matter relating ability generates query per vigilant (= lot roundtrips server).

the queries themselves overly challenging f.ex:

var activecontracts = customer.contracts.where(w => w.contractenddate == null);

whereas i review as:

var activecontracts = customer.activecontracts;

the sure reason me doing since minimize judicious errors biased i destiny wish change defines an active agreement i don't have redo lot code.

is there proceed mention ability sql should genereate. there proceed certain workable query below?

var singlecontractcustomers = db.customers.where(w => w.activecontracts.count() == 1);