Big Query 透视和聚合重复字段

Question

我想旋转“unitId”、“firebase_screen_class”字段，以便每个字段出现在单独的列中：

SELECT
  event.name,
  event_param.value.string_value AS ad_unit,
  COUNT(*) AS event_count
FROM
  `app_events_20170510`, 
  UNNEST(event_dim) AS event, 
  UNNEST(event.params) as event_param
WHERE
  event.name in ('Ad_requested', 'Ad_clicked', 'Ad_shown')
  and event_param.key in ('unitId', 'screen_class')
GROUP BY 1,2

我使用旧版 SQL 使用了以下查询，但它没有显示正确的聚合结果：

SELECT event_name, ad_unit, count(*) FROM
(
SELECT
  event_dim.name as event_name,
  MAX(IF(event_dim.params.key = "firebase_screen_class", event_dim.params.value.string_value, NULL)) WITHIN RECORD as firebase_screen_class,
  MAX(IF(event_dim.params.key = "unitId", event_dim.params.value.string_value, NULL)) WITHIN RECORD as ad_unit
FROM
  [app_events_20170510]
WHERE
  event_dim.name in ('Ad_requested','Ad_shown', 'Ad_clicked')
  and event_dim.params.key in ('unitId','screen_class')
)
group by 1,2

我正在寻找以下输出：

_________________________________________________________________________
| event_dim.name   | unitId         | screen_class         | count_events|
|__________________|________________|______________________|_____________|
| Ad_requested     | hpg            | socialFeed           |    520      |
|__________________|________________|______________________|_____________|
| Ad_shown         | hpg            | chat                 |    950      |
|__________________|________________|______________________|_____________|
| Ad_requested     | hni            | chat                 |    740      |
|__________________|________________|______________________|_____________|

所有事件Ad_requested、Ad_shown 和Ad_clicked 的参数具有相同的键（unitId、screen_class），并且每个键的值也相同（unitId：hpg、@987654332 @/screen_class:socialFeed,chat)

Answer 1

以下是 BigQuery 标准 SQL

#standardSQL
WITH `aggregation` AS (
  SELECT
    event.name,
    event_param.key,
    COUNT(*) AS event_count
  FROM
    `app_events_20170510`, 
    UNNEST(event_dim) AS event, 
    UNNEST(event.params) AS event_param
  WHERE
    event.name IN ('Ad_requested', 'Ad_clicked', 'Ad_shown')
    AND event_param.key IN ('unitId', 'firebase_screen_class','house')
  GROUP BY 1, 2
)
SELECT 
  name,
  MAX(IF(key = 'unitId', event_count, NULL)) AS unitId,
  MAX(IF(key = 'firebase_screen_class', event_count, NULL)) AS firebase_screen_class,
  MAX(IF(key = 'house', event_count, NULL)) AS house
FROM `aggregation`
GROUP BY name  

根据 cmets 中的说明进行更新：

#standardSQL
SELECT
  event.name,
  (SELECT value.string_value FROM UNNEST(event.params) WHERE key = 'unitId') AS unitId,
  (SELECT value.string_value FROM UNNEST(event.params) WHERE key = 'firebase_screen_class') AS firebase_screen_class,
  (SELECT value.string_value FROM UNNEST(event.params) WHERE key = 'house') AS house,
  COUNT(1) AS event_count
FROM `app_events_20170510`, UNNEST(event_dim) AS event
WHERE event.name IN ('Ad_requested', 'Ad_clicked', 'Ad_shown')
GROUP BY 1,2,3,4

... 出于好奇，我尝试使用旧版 SQL 复制查询 ... -

为 BigQuery Legacy SQL 添加了版本（纯粹出于学习目的，希望帮助那些考虑迁移到标准 SQL 的人，因为这里现在提供了相同任务的两个版本）

#legacySQL
SELECT name, product_id, source, firebase_event_origin, COUNT(1) AS event_count
FROM (
  SELECT event_dim.name AS name,
    MAX(IF(event_dim.params.key = 'unitId', event_dim.params.value.string_value, NULL)) WITHIN RECORD AS unitId,
    MAX(IF(event_dim.params.key = 'firebase_screen_class', event_dim.params.value.string_value, NULL)) WITHIN RECORD AS firebase_screen_class,
    MAX(IF(event_dim.params.key = 'house', event_dim.params.value.string_value, NULL)) WITHIN RECORD AS house,
  FROM FLATTEN([project:dataset.app_events_20170510], event_dim) AS event
  WHERE event_dim.name IN ('Ad_requested', 'Ad_clicked', 'Ad_shown')
)
GROUP BY 1, 2, 3, 4