access数据库的连接字符串以及数据库操作类

<!--access数据库连接方式-->
 <add name="QYTangConnectionString" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|Test.mdb" providerName="System.Data.OleDb" />

using System;
using System.Data;
using System.Data.OleDb;
using System.Configuration;

namespace QYTang.Gengerate
{
    /// <summary>
    /// OleDb操作类
    /// </summary>
    public abstract class OpOleDb
    {
        /// <summary>
        /// 获取数据库查询字符串
        /// </summary>
        public static string connStr = ConfigurationManager.ConnectionStrings["QYTangConnectionString"].ToString();

/// <summary>
        /// 根据一条sql,获取Dataset
        /// </summary>
        /// <param name="con">数据库连接字符串</param>
        /// <param name="cmdText">sql语句</param>
        /// <param name="parms">参数列表</param>
        /// <returns>Dataset</returns>
        public static DataSet GetDataSet(string con, string cmdText, OleDbParameter[] parms)
        {
            DataSet ds = new DataSet();
            OleDbCommand cmd = new OleDbCommand();
           
            OleDbConnection conn = new OleDbConnection(con);
            OleDbDataAdapter da = new OleDbDataAdapter();
            PrepareCommand(cmd, conn, CommandType.Text, cmdText, parms);
            da.SelectCommand = cmd;
            da.Fill(ds);
            cmd.Parameters.Clear();
            if (conn.State == ConnectionState.Open)
                conn.Close();
            return ds;
        }

/// <summary>
        /// 读取DataReader
        /// </summary>
        /// <param name="con">数据库连接字符串</param>
        /// <param name="cmdText">sql语句</param>
        /// <param name="parms">参数列表</param>
        /// <returns>DataReader</returns>
        public static OleDbDataReader GetDataRead(OleDbConnection conn, string cmdText, OleDbParameter[] parms)
        {
            OleDbCommand cmd = new OleDbCommand();
            PrepareCommand(cmd, conn, CommandType.Text, cmdText, parms);
            OleDbDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            cmd.Parameters.Clear();
            return dr;
        }

/// <summary>
        /// 插入、更新或删除操作
        /// </summary>
        /// <param name="con">数据库连接字符串</param>
        /// <param name="cmdText">sql语句</param>
        /// <param name="parms">参数列表</param>
        /// <returns>接受调整的行数 </returns>
        public static int Query(string con, string cmdText, OleDbParameter[] parms)
        {
            OleDbCommand cmd = new OleDbCommand();
            OleDbConnection conn = new OleDbConnection(con);
            PrepareCommand(cmd, conn, CommandType.Text, cmdText, parms);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            if (conn.State == ConnectionState.Open)
                conn.Close();
            return val;
        }

// 为数据查询做好准备
        static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, CommandType cmdType, string cmdText, OleDbParameter[] parms)
        {
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            cmd.CommandType = cmdType;
            if (parms != null)
            {
                for (int i = 0; i < parms.Length; i++)
                    cmd.Parameters.Add(parms[i]);
            }
        }
    }
}