困惑几天的问题，vs2008.控制台应用程序中添加的数据库服务，不能插入数据啊。求各位高手

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace 数据库
{
    class Program
    {
        static void Main(string[] args)
        {
            string dataDir = AppDomain.CurrentDomain.BaseDirectory;
            if (dataDir.EndsWith(@"\bin\Debug\") || dataDir.EndsWith(@"\bin\debug\"))
            {
                dataDir = (dataDir).Parent.Parent.FullName;
                AppDomain.CurrentDomain.SetData("DateDirectory", dataDir);
            }


            using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLexpress;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True "))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                     = "insert into Table1 (id,name) values (4,'yk')";
                    cmd.ExecuteNonQuery();



                  }
            }


        }
    }
}