C#如何操作access数据库

在program.cs的main函数中写下如下代码：

static void Main()

        {

            string dataDir = AppDomain.CurrentDomain.BaseDirectory;

            if (dataDir.EndsWith(@"\bin\Debug") || dataDir.EndsWith(@"\bin\Release\"))

            {

                dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;

                AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);

            }

            Application.EnableVisualStyles();

            Application.SetCompatibleTextRenderingDefault(false);

           // Application.Run(new FrmInport());

            Application.Run(new InExport());

        } 

在ClassDataBase.cs中写入如下代码

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Data.OleDb;

using System.Data;

namespace WindowsFormsApplication

{

    class ClassDataBase

    {

        static public string connString = "Provider = Microsoft.jet.OLEDB.4.0;Jet OLEDB:Database [email protected] x%E$ ^GF;Data Source =Database/SSQDYJ.mdb";

        static public OleDbConnection  openDatabaseConn() //打开Access数据库连接

        {

            OleDbConnection myconn=new OleDbConnection(connString);

            myconn.Open();

             //Error: value="~/Database/SSQDYJ.mdb"   //多余了“~/”字符

            //'F:\WindowsFormsApplication\WindowsFormsApplication3\WindowsFormsApplication3\bin\Debug\~\Database\SSQDYJ.mdb'

            //不是一个有效的路径。 确定路径名称拼写是否正确，以及是否连接到文件存放的服务器。           

            return  myconn;

        }

        static public void CloseConn(OleDbConnection myconn)//关闭Access数据库连接

        {

            if (myconn.State == ConnectionState.Open)

            {

                myconn.Close();

                myconn.Dispose();

            }

        }

        //        Command命令

        // 返回值        

        //ExecuteReader        // 返回一个 DataReader 对象        

        //ExecuteScalar        // 返回一个标量值        

        //ExecuteNonQuery      // 执行不返回任何行的命令        

        //ExecuteXMLReader     // 返回 XmlReader。 只用于 SqlCommand 对象

        static public DataTable CommandSql(OleDbConnection myconn, string sql,params string[] filedsValue)

        {

            if (myconn.State == ConnectionState.Closed) myconn.Open();

            OleDbCommand myCommand = new OleDbCommand(sql ,myconn);

            OleDbDataAdapter myAdapter = new OleDbDataAdapter(myCommand);

            DataSet myDataset = new DataSet();

            myAdapter.Fill(myDataset);

            CloseConn(myconn);

            return myDataset.Tables[0];

        }

    }

}

在调用的页面InExport写如下代码：

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Data.OleDb;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication3

{

    public partial class InExport : Form

    {

        static public OleDbConnection myconn=new OleDbConnection(); //定义全局变量

        public InExport()

        {

            InitializeComponent();                

            openOleconn();

            MessageBox.Show(Convert.ToString(myconn.State));

            MeeBox();

            MessageBox.Show(Convert.ToString(myconn.State));

        }

        public void MeeBox()

        {

            DataTable myTable = ClassDataBase.CommandSql(myconn, "select top 20 * from Fl_Issue order by LotIssue desc");

            MessageBox.Show(Convert.ToString( myTable.Rows.Count));

        }

        public void openOleconn()

        {

            myconn = ClassDataBase.openDatabaseConn();

            //MessageBox.Show(Convert.ToString( myconn.State));

            //ClassDataBase.CloseConn(myconn);

            //MessageBox.Show(Convert.ToString(myconn.State));

        }

        private void InExport_Load(object sender, EventArgs e)

        {

            DataView dv = new DataView();

            Control cr = new Control("显示一个控件");

        }

    }

}