sql - BigQuery 和标准 SQL : how to group by arbitrary day interval

Question

我是 BigQuery 和 SQL 的新手，一直在解决分组问题。在 BigQuery 中使用标准 SQL，我想按 X 天对数据进行分组。这是一个数据表:

event_id |    url    |          timestamp   
-----------------------------------------------------------
   xx         a.html      2016-10-18 15:55:16 UTC
   xx         a.html      2016-10-19 16:68:55 UTC
   xx         a.html      2016-10-25 20:55:57 UTC
   yy         b.html      2016-10-18 15:58:09 UTC
   yy         b.html      2016-10-18 08:32:43 UTC
   zz         a.html      2016-10-20 04:44:22 UTC
   zz         c.html      2016-10-21 02:12:34 UTC

我想从给定日期开始，每隔 X 天计算每个 url 上发生的每个事件的数量。例如:我如何以 3 天为间隔对它进行分组，我的第一个间隔从 2016-10-18 00:00:00 UTC 开始？另外，我可以将间隔的第 3 天分配给每一行吗？示例输出:

event_id |    url    |  count |        3dayIntervalLabel   
-----------------------------------------------------------
   xx         a.html      2           2016-10-20  --> [18th thru 20th]
   yy         b.html      2           2016-10-20
   zz         a.html      1           2016-10-20 
   zz         c.html      1           2016-10-23  --> [21th thru 23th]
   xx         a.html      1           2016-10-26  --> [24th thru 26th]

我添加了三个注释来阐明 3dayIntervalLabel 值。

一般来说，我希望解决:从日期 Y 开始按 X 天的间隔分组，并使用每个间隔的最终日期标记间隔。

如果需要更多说明，请告诉我。

如果您有兴趣，我还在 StackOverflow 上提出了关于使用滚动窗口对这些数据进行分组的类似问题(并得到了答案):initial question和 follow-up .

谢谢!

Answer 1

WITH dailyAggregations AS (
  SELECT 
    DATE(ts) AS day, 
    url, 
    event_id, 
    UNIX_SECONDS(TIMESTAMP(DATE(ts))) AS sec, 
    COUNT(1) AS events 
  FROM yourTable
  GROUP BY day, url, event_id, sec
),
calendar AS (
  SELECT day, DATE_ADD(day, INTERVAL 2 DAY) AS endday
  FROM UNNEST (GENERATE_DATE_ARRAY('2016-10-18', '2016-11-06', INTERVAL 3 DAY)) AS day
)
SELECT 
  event_id, 
  url,  
  SUM(events) AS `count`, 
  c.endday AS `ThreedayIntervalLabel`  
FROM calendar AS c
JOIN dailyAggregations AS a
ON a.day BETWEEN c.day AND c.endday
GROUP BY endday, url, event_id