我想请教一下，如何获取数据库中的信息并进行比较。  数据库用的是access。
麻烦哪位大虾指导一下！

连接数据库。
查询数据库。
得到数据库的数据。
关闭数据库。
比较。

恩 我知道这些步骤 就是不知道代码应该怎么写 能发一下吗 谢谢！

             if (textBox1.Text == ""||textBox2.Text=="")
            {
                MessageBox.Show("用户和密码不能为空！", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            string sqlstr = "Data Source=（local);Initial Catalog=Fm;Persist Security Info=True;User ID=sa;Password=";
            SqlConnection con = new SqlConnection(sqlstr);
            con.Open();
            string comstr = "select * from fm_user where username='" +textBox1.Text  + "'and password='"+textBox2.Text+"'";
            SqlCommand com = new SqlCommand(comstr, con);
            SqlDataReader dr = com.ExecuteReader();
            if (dr.HasRows)
            {
                 Form2 f2 =new Form2();
                 f2.show();
            }
            con.Close();
这是sql的添加using System.Data.SqlClient。
access的你连接字符自己查
添加using System.Data.OleDb
将SqlConnection 换成OleConnection
SqlCommand 换成OleCommand
SqlDataReader换成OleDataReader

看在我曾经和你一样在这个问题上打转。
你自己研究下吧！！

恩 谢了  问题 已解决 贴上我的给大家看看~
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 login
{
    public partial class Form1 : Form
    {
        
        private void Form1_Load(object sender, EventArgs e)
        {
            
        }
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (textBox1.Text.Trim() == "")
            {
                MessageBox.Show("请输入用户名");
            }
            else
            {
                string conStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb;";
                OleDbConnection myCon = new OleDbConnection(conStr);
                try
                {
                    myCon.Open();
                    //测试连接
                    //  MessageBox.Show("Success!" + myCon.State.ToString());
                    //使用DataSet
                    string myComStr = "SELECT * FROM Myuser WHERE [姓名]='" + textBox1.Text + " 'and [密码]='" + textBox2.Text + "'";
                    DataSet ds = new DataSet();
                    OleDbDataAdapter myCommand = new OleDbDataAdapter(myComStr, myCon);
                    myCommand.Fill(ds, "Myuser");
                    if (ds.Tables["Myuser"].Rows.Count == 0)
                    {
                        MessageBox.Show(" 密码错误\n" + "请您尽快注册!", "ERROR");
                    }
                    else
                    {
                        MessageBox.Show(textBox1.Text + "登陆成功", "恭喜");

                        return;

                    }
                }
                catch (OleDbException oe)
                {
                    MessageBox.Show(oe.Message);
                }
                finally
                {
                    myCon.Close();
                }
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            this.textBox1.Text = "";
            this.textBox2.Text = "";
        }


    }
}

大家一起学习