Change asp.net function from MySQL to SQL Server [closed]

I have those 2 methods in C# on asp.net:

DataTable dt;
        protected void Page_Load(object sender, EventArgs e)
        {            

                    //Fetch data from mysql database
                    MySqlConnection conn = new MySqlConnection("server=localhost;uid=root;
                         password=priya123;database=world;pooling=false;");
                    conn.Open();
                    string cmd = "select * from country limit 7";
                    MySqlDataAdapter dAdapter = new MySqlDataAdapter(cmd, conn);
                    DataSet ds = new DataSet();
                    dAdapter.Fill(ds);
                    dt=ds.Tables[0];
                    //Bind the fetched data to gridview
                    GridView1.DataSource = dt;
                    GridView1.DataBind();

        }

        protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            if(e.CommandName.Equals("detail"))
            {
                int index = Convert.ToInt32(e.CommandArgument);
                string code = GridView1.DataKeys[index].Value.ToString();

                    IEnumerable<DataRow> query = from i in dt.AsEnumerable()
                                      where i.Field<String>("Code").Equals(code)
                                       select i;
                    DataTable detailTable = query.CopyToDataTable<DataRow>();
                    DetailsView1.DataSource = detailTable;
                    DetailsView1.DataBind();

            }
        }

now I want to use SQL SERVER. I create a LINQ with DBML.. and have object called 'sdb' with the DataContext. I try to do change it with Lambda expression, but Got an error that the selected row from the lambda is not 'IEnumerable'. how can I casting that to SQL SERVER objects?

thanks!