添加引用
using System.Data.SqlClient;
[CODE] private void toolBar1_ButtonClick(object sender, ToolBarButtonClickEventArgs e)
        {
            string sqlstr = "";
            switch (e.Button.ImageIndex)
            {
                case 0:   //添加
                    sqlstr = "insert into table1 values(.....)";
                    break;
                case 1:  //修改
                    sqlstr = "update table1 set 字段=新值 where ....";
                    break;
                case 2:  //删除
                    sqlstr = "delete table1 where .....";
                    break;
            }
            dataSet(sqlstr);  //执行操作
        }[/CODE]
自定义方法        [CODE]void dataSet(string sqlstr)
        {
            SqlConnection myconn = new SqlConnection(数据库连接语句);   //建立连接
            SqlCommand cmd = new SqlCommand(sqlstr, myconn);            //定义命令
            try
            {
                myconn.Open();        //打开连接
                cmd.ExecuteNonQuery();  //执行数据操作
                MessageBox.Show("操作成功~!", "系统提示:");
            }
            catch (Exception expSql)
            {
                MessageBox.Show(expSql.ToString(), "出错啦!");   //显示错误
            }
            finally
            {
                myconn.Close();   //关闭连接
                myconn.Dispose(); //释放资源
                cmd.Dispose();    //释放资源
            }
        }[/CODE]