简单的ADO.NET通用数据库操作类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.OleDb;//
using System.Data;//

namespace ControlDB
{
    public class ControlDB
    {
        /// <summary>
        /// 创建一个数据链接
        /// </summary>
        /// <param name="path">数据库文件路径</param>
        /// <returns>数据链接</returns>
        public OleDbConnection strcon(string path)
        {
            OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path);
            return con;
        }

        /// <summary>
        /// 获取sql查询数据到数据表
        /// </summary>
        /// <param name="sqltext">sql查询语句</param>
        /// <param name="con">数据链接</param>
        /// <returns>数据表</returns>
        public DataTable GetDataTable(string sqltext, OleDbConnection con)
        {
            DataTable dt = new DataTable();
            OleDbDataAdapter adp = new OleDbDataAdapter(sqltext, con);
            try
            {
                con.Open();
                adp.Fill(dt);
                return dt;
            }
            catch (Exception e)
            {
                throw new SystemException(e.Message);
            }
            finally
            {
                con.Close();
            }
        }



        /// <summary>
        /// 获取sql查询数据到数据集
        /// </summary>
        /// <param name="sqltext">sql查询语句</param>
        /// <param name="con">数据链接</param>
        /// <returns>数据集</returns>
        public DataSet GetDataSet(string sqltext, OleDbConnection con)
        {
            DataSet ds = new DataSet();
            OleDbDataAdapter adp = new OleDbDataAdapter(sqltext, con);
            try
            {
                con.Open();
                adp.Fill(ds);
                return ds;
            }
            catch (Exception e)
            {
                throw new SystemException(e.Message);
            }
            finally
            {
                con.Close();
            }
        }



        /// <summary>
        /// 返回sql查询的第一行第一列
        /// </summary>
        /// <param name="sqltext">sql查询语句</param>
        /// <param name="con">数据链接</param>
        /// <returns>第一行第一列的字符串</returns>
        public string GetFirstValue(string sqltext, OleDbConnection con)
        {
            string strchar = "";
            OleDbCommand cmd = con.CreateCommand();
            cmd.CommandText = sqltext;
            try
            {
                con.Open();
                strchar = cmd.ExecuteScalar().ToString();
            }
            catch (Exception e)
            {
                throw new SystemException(e.Message);
            }
            finally
            {
                con.Close();

            }
            return strchar;
        }

        /// <summary>
        /// 执行SQL语句
        /// </summary>
        /// <param name="sqltext">SQL语句</param>
        /// <param name="con">数据链接</param>
        public void RunSqlCmd(string sqltext, OleDbConnection con)
        {
            OleDbCommand cmd = con.CreateCommand();
            cmd.CommandText = sqltext;
            try
            {
                con.Open();
                cmd.ExecuteNonQuery();
            }
            catch (Exception e)
            {
                throw new SystemException(e.Message);
            }
            finally
            {
                con.Close();
            }
        }

    }
}

protected void Button1_Click(object sender, EventArgs e)
        {
            
            ControlDB cd = new ControlDB();
            string sql = "select * from T1";//参数1
            OleDbConnection con = cd.strcon(@Server.MapPath("/App_Data/Database1.mdb"));//参数2

            DataTable dt = cd.GetDataTable(sql, con);
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }