现有程序，红色部分就是自己不会做的地方，自己在窗体里面建立了一个dataGridView，当点击button6的时候把自己建立的商品表导入到里面显示。
里面的代码是自己的从别的同学那里复制过来的，自己改可是改不出来。。。他不肯给我讲。。。能有人帮我解决么？万谢
using System;
using System.Collections.Generic;
using
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;


namespace WindowsFormsApplication27
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {//取消按钮
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox1.Focus();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //连接数据库
            string bd_connection = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=d:\\My Documents\\商品表.mdb";
            OleDbConnection conn = new OleDbConnection(bd_connection);
            //打开数据
            conn.Open();

            //操作数据
            OleDbCommand cmd = new OleDbCommand();
            cmd.Connection = conn;
             = "insert into 商品表(商品名称,商品单价,数量)values('" + textBox1.Text + "'," + textBox2.Text + "," + textBox3.Text + ")";
            cmd.ExecuteNonQuery();

            //关闭数据库
            conn.Close();

            
            
            
            MessageBox.Show("商品添加成功");
            
        }

        private void button3_Click(object sender, EventArgs e)
        {
           
            //查询  
            string db_connection = "Provider= Microsoft.Jet.OLEDB.4.0;Data Source =d:\\My Documents\\商品表.mdb";
            OleDbConnection conn = new OleDbConnection(db_connection);

            conn.Open();

            OleDbCommand cmd = new OleDbCommand();
            cmd.Connection=conn;
             = "select * from 商品表 where 商品名称='" + textBox1.Text + "'";

            OleDbDataReader reader = cmd.ExecuteReader();
            
            if(reader.HasRows)
            {
               
               
                    reader.Read();
                    textBox2.Text = reader["商品单价"].ToString();
                    textBox3.Text = reader["数量"].ToString();
                    
            }
            else
            {
                MessageBox.Show("此商品不存在!");
                textBox1.Text = "";
                textBox1.Focus();
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            button3.Enabled = false;
            button4.Enabled = false;
            button5.Enabled = false;
            button1.Enabled = false;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            //修改
            string db_connection = "Provider=Microsoft.Jet.OlEDB.4.0;Data Source=d;\\My Documents\\商品表.mdb";
            OleDbCommand conn = new OleDbCommand(db_connection);
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (textBox1.Text != "")
            {

                button3.Enabled = true;

            }
        }

        private void textBox3_TextChanged(object sender, EventArgs e)
        {
            if (textBox1.Text!=""&&textBox2.Text!=""&&textBox3.Text!="")
                button1.Enabled=true;
        }

        private void button6_Click(object sender, EventArgs e)
        {

            string db_connection = "Provider= Microsoft.Jet.OLEDB.4.0;Data Source =d:\\My Documents\\商品表.mdb";
            OleDbConnection conn = new OleDbConnection(db_connection);
            conn = new OleDbConnection(db_connection);
            conn.Open();
            string query1 = "select 商品名称,数量 from 商品表 order by 数量 desc";
            OleDbConnection msda = new OleDbDataAdapter(db_connection);
            msda = new OleDbDataAdapter(query1, conn);
            msda.Fill(ds, "商品表");
            dataGridView1.DataSource = ds.Tables["商品表"];
            conn.Close();
        }

        
    }
}

[ 本帖最后由 耐个 于 2013-5-23 23:14 编辑 ]

求解脱啊。。。坐等

好吧我自己解脱了，看书找到了。。。
 private void button6_Click(object sender, EventArgs e)
        {

            string db_connection = "Provider= Microsoft.Jet.OLEDB.4.0;Data Source =d:\\My Documents\\商品表.mdb";
            OleDbConnection conn = new OleDbConnection(db_connection);
            string query1 = "select 商品名称,数量 from 商品表 order by 数量 desc";
            OleDbDataAdapter sda = new OleDbDataAdapter(query1,conn);
            DataSet ds = new DataSet();
            sda.Fill(ds, "商品表");
            dataGridView1.DataSource = ds.Tables[0];
            
        }