SelectMany flattens queries that return lists of lists. For example public class PhoneNumber { public string Number { get; set; } } public class Person { public IEnumerable<PhoneNumber> PhoneNumbers { get; set; } public string Name { get; set; } } IEnumerable<Person> people = new List<Person>(); // Select gets a list of lists of phone … Read more
It goes something like: from t1 in db.Table1 join t2 in db.Table2 on t1.field equals t2.field select new { t1.field2, t2.field3} It would be nice to have sensible names and fields for your tables for a better example. 🙂 Update I think for your query this might be more appropriate: var dealercontacts = from contact … Read more
Yes, both will give you deferred execution. The difference is that IQueryable<T> is the interface that allows LINQ-to-SQL (LINQ.-to-anything really) to work. So if you further refine your query on an IQueryable<T>, that query will be executed in the database, if possible. For the IEnumerable<T> case, it will be LINQ-to-object, meaning that all objects matching … Read more