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

[jdjiadian]

请帮我把以下方法转成linq 的方法 谢谢啊。。asp.net的

public static string ReadIdDate()
{
StringBuilder texts = new StringBuilder();

string sql = "select top 1 id from BusinessWaybill order by id desc";

string source = "Data Source=1.1.1.1;Initial Catalog=testDB;Persist Security Info=True;User ID=sa;Password=***";

using (SqlConnection conn = new SqlConnection(source))
{
SqlCommand com = new SqlCommand(sql, conn);

conn.Open();

SqlDataReader r = com.ExecuteReader();
try
{
while (r.Read())
{
texts.Append(r.GetInt32(0).ToString());
}
}
finally
{
r.Close();
}
}
return texts.ToString();
}

[newtee]

 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

[發糞塗牆]

引用 1 楼 zhuankeshumo 的回复:

C# code ? 1234 DataClasses1DataContext db = new DataClasses1DataContext(); var s = (from p in db.BusinessWaybill orderby p.id descending select p.id).First……

无比膜拜

[newtee]

[jiangshun]

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

[骑着蜗牛去爬山]

FirstOrDefault First Take(1) 等方法都可以

[你的选择B]

                //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());