请教高手 linq to sql 如何写 select top1 id 的方法

Question

本帖最后由 jdjiadian 于 2012-12-10 17:05:26 编辑

Answer 1

 DataClasses1DataContext db = new DataClasses1DataContext();
            var s = (from p in db.BusinessWaybill  orderby p.id descending
                    select p.id).First();
     texts.Append(s..ToString());
不知道对不对

Answer 2

StringBuilder texts = new StringBuilder();
BusinessWaybil.Select(s=>s.id).OrderByDescending(s=>s.id).FirstOrDefault().ToList().Aggregate((s1,s2)=> texts.Append(s1+""+s2));

Answer 3

FirstOrDefault
First
Take(1)
等方法都可以

Answer 4

                //LINQ To SQL
                int result = (from u in db.Orders
                              orderby u.OrderID descending
                              select u.OrderID).FirstOrDefault();                StringBuilder sb = new StringBuilder();
                if (result != 0)
                    sb.Append(result.ToString());                //lambda
                int result1 = db.Orders.Select(c => c.OrderID).OrderByDescending(c => c).FirstOrDefault();
                if (result1 != 0)
                    sb.Append(result1.ToString());