Question

我使用标准SQL for Bigquery。我需要找到早上，下午或晚上发生的所有事件。我可以做这样的事情

WHERE TIMESTAMP_MICROS(event.timestamp_micros) BETWEEN '2017-04-01 12:00:00' AND '2017-06-01 16:00:00'

但我只需要没有约会的时间。有没有办法只按时间查询？

Answer 1

在BigQuery Standard SQL中你可以使用

EXTRACT(HOUR FROM TIMESTAMP_MICROS(event.timestamp_micros))

以下是用法示例

#standardSQL
SELECT 
  CASE 
    WHEN hr >= 4 AND hr < 12 THEN 'morning' 
    WHEN hr >= 12 AND hr < 15 THEN 'afternoon'
    WHEN hr >= 15 AND hr < 17 THEN 'late_afternoon'
    WHEN hr >= 17 AND hr < 19 THEN 'evening'
    WHEN hr >= 19 AND hr < 21 THEN 'late_evening'
    ELSE 'night' 
  END AS day_part
FROM `dataset.yourtable`, 
UNNEST([EXTRACT(HOUR FROM TIMESTAMP_MICROS(event.timestamp_micros))]) AS hr

Answer 2

有两种根本不同的方法。一种方法是将值转换为时间戳，然后使用时间戳 - 例如将值格式化为小时。

另一个是使用微秒。你可以用除法和模数运算做你想做的事。所以，要计算一天中的小时：

where mod(cast(event.timestamp_micros / (1000000 * 60 * 60) as int64), 24) between 12 and 13

请注意，这时间从12:00:00到13：59.59.999999。

Answer 3

BigQuery有一个TIME type可以使用。例如，

SELECT
  COUNTIF(time BETWEEN '04:00:00' AND '12:00:00') AS morning_events,
  COUNTIF(time BETWEEN '12:00:00' AND '20:00:00') AS evening_events,
  COUNTIF(time < '04:00:00' OR time > '20:00:00') AS night_events
FROM (
  SELECT
    EXTRACT(TIME FROM TIMESTAMP_MICROS(event.timestamp_micros)) AS time
  FROM YourTable
);

Bigquery在事件发生时查询

3 个答案: