在数据库中删除一个列时抛出异常，望哥哥姐姐们帮忙看一下。


#region Using Region
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
#endregion

namespace DeletingData
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                SqlConnection con = new SqlConnection(@"Server=(local);Integrated Security=True;Database=图书馆管理系统");
                SqlDataAdapter adpt = new SqlDataAdapter("select * from administrator",con);
                SqlCommandBuilder cmdbldr = new SqlCommandBuilder(adpt);
                DataSet dtst = new DataSet();
                adpt.Fill(dtst,"table");

                Console.WriteLine("Rows before change is "+dtst.Tables["table"].Rows.Count);

                //Create a key
                DataColumn[] keys = new DataColumn[1];
                keys[0] = dtst.Tables["table"].Columns["UserName"];
                dtst.Tables["talbe"].PrimaryKey = keys;　//运行到这一句时出错，异常提示：未将对象引用设置到对象的实例

                //Searching for row
                DataRow fRow = dtst.Tables["talbe"].Rows.Find("54456");

                if (fRow != null)
                {
                    Console.WriteLine("54456 is found.");
                    Console.WriteLine("Removing now...");
                    fRow.Delete();

                    adpt.Update(dtst,"table");
                }

                Console.WriteLine("Rows after chang is " + dtst.Tables["talbe"].Rows.Count);
                con.Close();
                Console.WriteLine("Press any key to exit...");




            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                Console.ReadKey();
            }
        }
    }
}

[[it] 本帖最后由 mona 于 2008-12-13 08:47 编辑 [/it]]

自己已经找到错误了，dtst.Tables["table"]，dtst里的表名弄错了。