示例：组聚合求和

获取 2013 年第一季度每个月的总量：

    SELECT symbol, 
        seq_search(day, 20130101, 20130331) as trade_date,
        volume@trade_date as "volume",
        seq_group_agg_sum(volume@trade_date, trade_date/100) as "month_vol"
    FROM Quote WHERE symbol='IBM';
     
    symbol
    trade_date{}
    volume{}
    month_vol{}
    ------------------------------------------------------------------------------
    IBM
    {20130102, 20130103, 20130104, 20130107, 20130108,
    20130109, 20130110, 20130111, 20130114, 20130115,
    20130116, 20130117, 20130118, 20130122, 20130123,
    20130124, 20130125, 20130128, 20130129, 20130130,
    20130131,
    20130201, 20130204, 20130205, 20130206, 20130207,
            
    20130208, 20130211, 20130212, 20130213, 20130214,
            
    20130215, 20130219, 20130220, 20130221, 20130222,
            
    20130225, 20130226, 20130227, 20130228,
            
    20130301, 20130304, 20130305, 20130306, 20130307,
    20130308, 20130311, 20130312, 20130313, 20130314,
    20130315, 20130318, 20130319, 20130320, 20130321,
    20130322, 20130325, 20130326, 20130327, 20130328}
    {4234226, 3644876, 3380159, 2862276, 3028071,
    3211997, 3608049, 3880567, 4172922, 4172034,
    2962820, 3884254, 4559773, 7159219, 12530410,
    4447108, 3358887, 2823615, 3617058, 2998524,
    3091406,
    3371154, 3188819, 3636837, 3624103, 3076793,
            
    2893254, 2944651, 2461779, 2169757, 3294126,
            
    3627887, 2998317, 3715311, 3923051, 3107976,
            
    3845476, 3391562, 4185545, 4689998,
            
    3309434, 3693365, 3807706, 3594899, 3884317,
    3700786, 3049701, 3592096, 3356946, 5505584,
    7936544, 3006125, 3198577, 3020648, 5830566,
    3031457, 3242463, 2300240, 3223381, 3752999}
    {87628251, 64146396, 76037834}

我们可以对上述输出进行如下分析：

• 为了方便起见，将交易日期和成交量序列的输出值按月份进行划分。
• 序列 month_vol 显示每个月的“组聚合求和”（计算方式为 trade_date/100，例如 20130101/100 = 201301）。
• 二月份的成交量总计如下，从而在序列 month_vol 中生成相应的值 64146396：

交易日	成交量
20130201	3371154
20130204	3188819
20130205	3636837
20130206	3624103
20130207	3076793
20130208	2893254
20130211	2944651
20130212	2461779
20130213	2169757
20130214	3294126
20130215	3627887
20130219	2998317
20130220	3715311
20130221	3923051
20130222	3107976
20130225	3845476
20130226	3391562
20130227	4185545
20130228	4689998
2月总计	64146396

要运行此示例脚本以演示此选择语句，请在 samples/xsql/scripts/financial 目录中使用以下命令：

    x 10