修改数据集中的数据

//注意如何给DataTable添加新行

DataRow newRow=dt.NewRow();//调用方法

.......

dt.Rows.Add(newRow);

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 sql =@"select * from employees where country='UK'";
            try
            { 
            
              //Create the DataAdapter
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = new SqlCommand(sql,conn);
                //Create dataSet and fill it
                DataSet ds = new DataSet();
                da.Fill(ds,"employees");
                //get the table reference
                DataTable dt=ds.Tables["employees"];
                //first name to be nullable
                dt.Columns["firstname"].AllowDBNull = true;
                //modify city in the first row
                dt.Rows[0]["city"] = "Xuzhou";
                //Add a row
                DataRow newRow =dt.NewRow();
                newRow["firstname"] = "Zhuo";
                newRow["lastname"] = "bin";
                newRow["titleofcourtesy"] = "123";
                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"]);
                }
            }
            catch (SqlException ex)
            {
                Console.WriteLine("The error:{0}", ex.Message);
            }
            finally
            {
                conn.Close();
            }
            Console.ReadLine();
        }
    }
}