net Access数据库连接类 通用

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.OleDb;

public class DBcon
{
    OleDbConnection con = null;
    public DBcon()
    {
       
    }
    public void getCon()
    {        
           con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;   Data Source="+HttpContext.Current.Request.MapPath("~")+"//hawei.mdb");
          
    }
    public void closeCon()
    {
        if (con.State == ConnectionState.Open)
        {
            con.Close();
        }
    }
    public DataTable select(string sql)
    {
        this.getCon();
        DataSet ds = new DataSet();
        OleDbDataAdapter sda = new OleDbDataAdapter(sql,con);
        sda.Fill(ds);
        return ds.Tables[0];
    }

    public int excute(string sql)
    {
        this.getCon();
        con.Open();
        OleDbCommand scmd = new OleDbCommand(sql,con);
        int x = scmd.ExecuteNonQuery();
        this.closeCon();
        return x;
    }

    public DataTable select()
    {
        throw new Exception("The method or operation is not implemented.");
    }
}