C#2005 一个简单的Access数据库访问类

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

namespace xxxxx

{
    /// <summary>
    /// Access数据库访问类
    /// </summary>
    public class DataAccess
    {
        private static OleDbConnection conn = new OleDbConnection();
        private static OleDbCommand comm = new OleDbCommand();
        private static string asscessPath = @"./PoliScan.mdb";

        /// <summary>
        /// 设置Access数据库路径
        /// </summary>
        /// <param name="path">完整的路径字符串</param>
        public static void SetAccessPath(string path)
        {
            asscessPath = path;
        }
       
        /// <summary>
        /// 打开数据库
        /// </summary>
        /// <returns>成功返回 true；失败返回 false；异常时抛出异常</returns>
        public static bool OpenConnection()
        {
            bool retval = false;
 
            if (conn.State != ConnectionState.Open)
            {
                conn.ConnectionString = @"Provider=Microsoft.Jet.OleDb.4.0;Data Source=" + asscessPath;
                comm.Connection = conn;
                try
                {
                    conn.Open();
                    if (conn.State == ConnectionState.Open)
                    {
                        retval = true;
                    }
                }
                catch (Exception e)
                {
                    throw new Exception(e.Message);
                }

            }
            else
            {
                retval = true;
            }

            return retval;
        }

        /// <summary>
        /// 关闭数据库并释放内存资源
        /// </summary>
        public static void CloseConnection()
        {
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
                conn.Dispose();
                comm.Dispose();
            }
        }//关闭数据库

        /// <summary>
        /// 执行sql语句
        /// </summary>
        /// <param name="sqlCommand">完整的sql语句</param>
        /// <returns>成功返回受影响的行数；失败返回负数；异常时抛出异常</returns>
        public static int ExcuteSql(string sqlCommand)
        {
            int retval = -999;

            try
            {
                OpenConnection();
                comm.CommandType = CommandType.Text;
                comm.CommandText = sqlCommand;
                retval = comm.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }

            return retval;
        }

        /// <summary>
        /// 通过指定sql命令获取记录集,返回DataSet对象
        /// </summary>
        /// <param name="sqlCommand">sql命令</param>
        /// <returns>成功返回DataSet对象；异常时抛出异常</returns>
        public static DataSet GetDataSet(string sqlCommand)
        {
            DataSet ds = new DataSet();
            OleDbDataAdapter da = new OleDbDataAdapter();
            try
            {
                OpenConnection();
                comm.CommandType = CommandType.Text;
                comm.CommandText = sqlCommand;
                da.SelectCommand = comm;
                da.Fill(ds);
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
          
            return ds;
        }//返回指定sql语句的dataset

        /// <summary>
        /// 【保留】通过指定sql命令获取数据库表,返回DataTable对象
        /// </summary>
        /// <param name="sqlCommand">sql命令</param>
        /// <returns>成功返回DataTable对象；异常时抛出异常</returns>
        public static DataTable GetDataTable(string sqlCommand)
        {
            DataTable dt = new DataTable();
            OleDbDataAdapter da = new OleDbDataAdapter();
            try
            {
                OpenConnection();
                comm.CommandType = CommandType.Text;
                comm.CommandText = sqlCommand;
                da.SelectCommand = comm;
                da.Fill(dt);
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
           
            return dt;
        }

        /// <summary>
        /// 【保留】通过指定sql命令获取视图，返回DataView对象
        /// </summary>
        /// <param name="sqlCommand"></param>
        /// <returns></returns>
        public static DataView GetDataView(string sqlCommand)
        {
            OleDbDataAdapter da = new OleDbDataAdapter();
            DataSet ds = new DataSet();
            DataView dv = new DataView();
            try
            {
                OpenConnection();
                comm.CommandType = CommandType.Text;
                comm.CommandText = sqlCommand;
                da.SelectCommand = comm;
                da.Fill(ds);
                dv = ds.Tables[0].DefaultView;
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
  
            return dv;
        }
    }
}