@Prog! - ASP.NET(C#) AJAX -

using System;
using System.Linq;
using System.IO;

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[ args)
        {
            Test1 db = new Test1(Settings1.Default.ConnectionString);

            StreamWriter sw = new StreamWriter(@"d:\log.txt");
            sw.AutoFlush = true;
            TextWriter tw = TextWriter.Synchronized(sw);

            db.Log = tw;

            int? num = null;

            var rs = from t in db.Table_1 where t.Number == (num ?? t.Number) select t;

            foreach (var r in rs) Console.WriteLine(r.Number);

            Console.Read();
        }
    }
}

SELECT [t0].[ID], [t0].[Number]
FROM [dbo].[Table_1] AS [t0]
WHERE [t0].[Number] = (COALESCE(@p0,[t0].[Number]))
-- @p0: Input Int (Size = 0; Prec = 0; Scale = 0) [Null]
-- Context: SqlProvider(Sql2005) Model: AttributedMetaModel Build: 3.5.21022.8

using System;
using System.Linq;
using System.IO;

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[ args)
        {
            Test1 db = new Test1(Settings1.Default.ConnectionString);

            StreamWriter sw = new StreamWriter(@"d:\log.txt");
            sw.AutoFlush = true;
            TextWriter tw = TextWriter.Synchronized(sw);

            db.Log = tw;

            int? num = 1111;

            var rs = from t in db.Table_1 where t.Number == (num ?? t.Number) select t;

            foreach (var r in rs) Console.WriteLine(r.Number);

            Console.Read();
        }
    }
}