C# DB2(ACCESS)数据库通用类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.OleDb;
using System.Data;

namespace Bn6.DBUtility
{
    public class DB2Helper
    {
        private OleDbConnection conn;
        private OleDbDataAdapter oda = new OleDbDataAdapter();
        private OleDbCommand cmd;
        private DataSet myds = new DataSet();
        private string filePath = AppDomain.CurrentDomain.BaseDirectory + "DB2DataBase\\SupTrackPms_American.accdb";

        public DB2Helper()
        {
            //access2000-2003
            //数据库连接字符串： ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=数据库名.mdb";
            //access2007-2010
            //数据库连接字符串：ConStr = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=数据库名.accdb";
            conn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath);
        }

        private static DB2Helper _instence;
        /// <summary>
        /// AccessHelper单例
        /// </summary>
        public static DB2Helper Instence
        {
            get
            {
                if (_instence == null)
                    _instence = new DB2Helper();
                return _instence;
                
            }
        }

        public DataSet GetDS(string strSQL)
        {
            myds = new DataSet();
            oda = new OleDbDataAdapter(strSQL, conn);
            oda.Fill(myds);
            return myds;
        }

        public DataSet GetDS2(string strSQL, int si, int mi)
        {
            conn.Open();
            myds = new DataSet();
            oda = new OleDbDataAdapter(strSQL, conn);
            oda.Fill(myds, si, mi, "tab1");
            conn.Close();
            return myds;

        }

        public bool SetDS(string strSQL)
        {
            conn.Open();
            cmd = new OleDbCommand(strSQL, conn);
            cmd.ExecuteNonQuery();
            conn.Close();
            return true;
        }
    }
}