BigQuery SQL: 无法查询重复字段的叉积 /

Question

我的目标是从所有访问者中过滤，只分析客户（在 customDimension.index =2 中，然后进一步过滤特定类型的客户浏览量。

SELECT customDimensions.value AS CustomerID,
SUM(totals.pageviews) as page_views,
SUM(CASE WHEN hits.type = 'PAGE' AND hits.contentGroup.contentGroup2 = 'important' THEN 1 ELSE 0 END) AS important_pageviews
FROM `xxxxxxxx.ga_sessions_20180415`
WHERE customDimensions.index = 2
GROUP BY CustomerID

我得到的错误是（使用标准SQL）：

Error: Cannot access field index on a value with type
ARRAY<STRUCT<index INT64, value STRING>> at [5:24]

旧版 SQL:

Error: Cannot query the cross product of repeated fields customDimensions.index and hits.contentGroup.contentGroup2.

编辑：

SELECT cd.value AS CustomerID,
SUM(totals.pageviews) as page_views,
SUM(CASE WHEN hits.type = 'PAGE' AND hits.contentGroup.contentGroup2 = 'important' THEN 1 ELSE 0 END) AS important_pageviews
FROM `xxxxxxxx.ga_sessions_20180415`,
UNNEST(customDimensions) AS cd
WHERE cd.index = 2
GROUP BY CustomerID

returns:

Error: Cannot access field type on a value with type ARRAY<STRUCT<hitNumber INT64, time INT64, hour INT64, ...>> at [3:20]

我尝试使用 UNNEST(hits.type) = 'PAGE' AND UNNEST(hitscontentGroup.contentGroup2) = 'important' 更正 3:20 行，这给出了 Error: Syntax error: Unexpected keyword UNNEST at [3:15]

Answer 1

由于 customDimensions 是一个数组，您需要 unnest 这个数组才能引用它的内容，请参阅下面的 StandardSQL 示例，其中我从 BigQuery 中的 Google Analytics 数据中取消嵌套 UserID：

SELECT customDimension.value AS UserID
FROM `my.project.data` AS t
  CROSS JOIN UNNEST(t.customdimensions) AS customDimension
  WHERE customDimension.index = 2

BigQuery SQL: 无法查询重复字段的叉积 /

BigQuery SQL: Cannot query the cross product of repeated fields /

sql

google-bigquery

legacy-sql