c#操作数据类之一

    /// <summary>     /// 返回指定Sql语句的DataSet     /// </summary>     /// <param name="sqlstr">传入的Sql语句</param>     /// <returns>DataSet</returns>     public static DataSet dataSet(string sqlstr)    {        DataSet ds = new DataSet();        OleDbDataAdapter da = new OleDbDataAdapter();        try        {            openConnection();            comm.CommandType = CommandType.Text;            comm.CommandText = sqlstr;            da.SelectCommand = comm;            da.Fill(ds);        }        catch (Exception e)        {            throw new Exception(e.Message);        }        finally        {            closeConnection();        }        return ds;    }    /// <summary>     /// 返回指定Sql语句的DataSet     /// </summary>     /// <param name="sqlstr">传入的Sql语句</param>     /// <param name="ds">传入的引用DataSet对象</param>     public static void dataSet(string sqlstr, ref DataSet ds)    {        OleDbDataAdapter da = new OleDbDataAdapter();        try        {            openConnection();            comm.CommandType = CommandType.Text;            comm.CommandText = sqlstr;            da.SelectCommand = comm;            da.Fill(ds);        }        catch (Exception e)        {            throw new Exception(e.Message);        }        finally        {            closeConnection();        }    }