ole辅助类sqlhelperaccess

namespace dal
{
    public class olehelp
    {
        private OleDbConnection conn = null;
        private OleDbCommand cmd = null;
        private OleDbDataReader oddr = null;
        public olehelp()
        {
            conn = new OleDbConnection(ConfigurationManager.AppSettings["connstring"].ToString());
        }
        private OleDbConnection getconn()
        {

            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }
            return conn;
        }
        /// <summary>
        /// 执行不带参数的增删改语句
        /// </summary>
        /// <param name="cmdtext">增删改语句</param>
        /// <param name="ct">命令行模式</param>
        /// <returns>数值</returns>
        public int execnonquery(string cmdtext, CommandType ct)
        {
            int res;
            try
            {
                cmd = new OleDbCommand(cmdtext, getconn());
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {

                throw ex;
            }
            finally
            {
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                }
            }
            return res;
        }
        /// <summary>
        /// 执行带参数的增删改语句
        /// </summary>
        /// <param name="cmdtext"></param>
        /// <param name="paras"></param>
        /// <param name="ct"></param>
        /// <returns></returns>
        public int execnonquery(string cmdtext, OleDbParameter[] paras, CommandType ct)
        {
            int res;
            using (cmd = new OleDbCommand(cmdtext, getconn()))
            {
                cmd.Parameters.AddRange(paras);
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
            }
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
            }

            return res;
        }
        /// <summary>
        /// 执行不带参数查询语句
        /// </summary>
        /// <param name="cmdtext">语句</param>
        /// <param name="ct">命令格式</param>
        /// <returns>数据表</returns>
        public DataTable execquery(string cmdtext, CommandType ct)
        {

            DataTable dt = new DataTable();
            cmd = new OleDbCommand(cmdtext, getconn());
            cmd.CommandType = ct;
            using (oddr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(oddr);
            }

            return dt;
        }
        /// <summary>
        /// 执行带参数的查询语句
        /// </summary>
        /// <param name="cmdtext">语句</param>
        /// <param name="paras">参数</param>
        /// <param name="ct">命令格式</param>
        /// <returns>数据表</returns>
        public DataTable execquery(string cmdtext, OleDbParameter[] paras, CommandType ct)
        {

            DataTable dt = new DataTable();
            cmd = new OleDbCommand(cmdtext, getconn());
            cmd.Parameters.AddRange(paras);
            cmd.CommandType = ct;
            using (oddr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(oddr);
            }
            return dt;
        }

    }
}

要附加上这些：

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