SqlDataAdapter的InsertCommand属性

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            SqlConnection conn = new SqlConnection("Server=zhuobin;uid=sa;pwd=zhuobin;database=Northwind");
            string qry = "select * from employees where country='UK'";
            string ins = @"insert into employees(firstname,lastname,titleofcourtesy,city,country)values(@firstname,@lastname,@titleofcourtesy,@city,@country)";
            try
            { 
              //create the Adapter
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = new SqlCommand(qry,conn);
                //create the DataSet
                DataSet ds = new DataSet();
                da.Fill(ds,"employees");
                //get the table reference
                DataTable dt = ds.Tables["employees"];
                //Add a new row
                DataRow newRow = dt.NewRow();
                newRow["Firstname"] = "Zhuo";
                newRow["lastname"] = "bin";
                newRow["titleofcourtesy"] = "Sir";
                newRow["city"] = "Tengzhou";
                newRow["country"] = "China";
                dt.Rows.Add(newRow);
                //display the data 
                foreach (DataRow row in dt.Rows)
                {
                    Console.WriteLine("{0}{1}{2}",row["firstname"].ToString().PadRight(15),row["lastname"].ToString().PadLeft(25),row["city"]);
                }
                //insert into employees
                //create command
                SqlCommand cmd = new SqlCommand(ins,conn);
                //map parameters
                cmd.Parameters.Add("@firstname",SqlDbType.NVarChar,10,"firstname");
                cmd.Parameters.Add("@lastname",SqlDbType.NVarChar,10,"lastname");
                cmd.Parameters.Add("@titleofcourtesy",SqlDbType.NVarChar,10,"titleofcourtesy");
                cmd.Parameters.Add("@city",SqlDbType.NVarChar,15,"city");
                cmd.Parameters.Add("@country",SqlDbType.NVarChar,15,"country");
                //insert into employees
                da.InsertCommand = cmd;
                da.Update(ds,"employees");

            }
            catch (SqlException ex)
            {
                Console.WriteLine("The error:{0}", ex.Message);
            }
            finally
            {
                conn.Close();
            }
            Console.ReadLine();         
        }
    }
}