Linq to Entities simple group query

问题

How to write (simple) LINQ to Entities query that groups elements by some attribut and count them?

SELECT answernumber, count(answerID) FROM answers
WHERE questionID = id
GROUB BY answernumber
ORDERBY answernumber;

That should be simple but i don't know how to write it.

回答1:

var query = answers
   .GroupBy(a => a.answernumber, a => a, (k, g) => new {answernumber = k, Count = g.Count()})
   .OrderyBy(i => i.answernumber);

Or the other way:

var query2 = from a in answers
         group a by a. answernumber into g
         orderby g.Key
         select new { answernumber = g.Key, Count = g.Count() };

来源：https://stackoverflow.com/questions/1358082/linq-to-entities-simple-group-query