/// <summary>

        /// describe:支持 DataSet

        /// </summary>

        /// <param name="cnn"></param>

        /// <param name="adapter"></param>

        /// <param name="sql"></param>

        /// <param name="param"></param>

        /// <param name="buffered"></param>

        /// <param name="commandTimeout"></param>

        /// <param name="commandType"></param>

        /// <returns></returns>

        public static DataSet ExecuteDataSet(this IDbConnection cnn, IDbDataAdapter adapter, string sql, object param = null, bool buffered = true, int? commandTimeout = null, CommandType? commandType = null)

        {

            var ds = new DataSet();

            var command = new CommandDefinition(sql, (object)param, null, commandTimeout, commandType, buffered ? CommandFlags.Buffered : CommandFlags.None);

            var identity = new Identity(command.CommandText, command.CommandType, cnn, null, param == null ? null : param.GetType(), null);

            var info = GetCacheInfo(identity, param, command.AddToCache);

            bool wasClosed = cnn.State == ConnectionState.Closed;

            if (wasClosed) cnn.Open();

            adapter.SelectCommand = command.SetupCommand(cnn, info.ParamReader);

            adapter.Fill(ds);

            if (wasClosed) cnn.Close();

            return ds;

        }