其实非常简单，就是用SqlDataAdapter的update方法就行了。主要代码例如下所示：
private void update()

    {

      string link = ConfigurationSettings.AppSettings["link_local"].ToString();

      SqlConnection conn = new SqlConnection(link);

      SqlDataAdapter da = new SqlDataAdapter("SELECT order_id, contract FROM linhai", conn);

      DataSet ds = new DataSet();

      da.Fill(ds, "linhai"); 

      da.UpdateCommand = new SqlCommand("UPDATE linhai SET contract = @contract " + "WHERE order_id = @order_id" , conn);

      da.UpdateCommand.Parameters.Add("@contract", SqlDbType.NVarChar, 15, "contract");

      da.UpdateCommand.Parameters.Add("@order_id", SqlDbType.NVarChar, 15, "order_id");

      ds.Tables["linhai"].Rows[0]["contract"] = "PPP";

      da.Update(ds.Tables[0]);

    }