Clickhouse实现累计求和cumulative sum

源表数据如下：

需求是按照省份和时间分类，每天累计求和，需求的结果如下：
（每天的数据都要按照省份将之前的订单数目进行累加）

需要借助clickhouse的array系列函数实现: ArrayFunction

SELECT
    time,
    province,
    arraySum(arraySlice(order_cnts, 1, i)) AS order_cnt_sum  
FROM
(
    SELECT groupArray(order_cnt) AS order_cnts,
           groupArray(time) AS times,
           groupArray(province) AS provinces
    FROM
    (
        SELECT *
        FROM test_table order by time
    ) group by province
)
ARRAY JOIN
    times as time,
    provinces AS province,
    arrayEnumerate(order_cnts) AS i;