UNNEST(hit.eCommerceAction)，谷歌 Bigquery

Question

我使用相同的逻辑来取消嵌套 hit.eCommerceAction，但它不像其他字段那样工作。对这个问题有任何帮助吗？另外，max(if()) 函数是否是用于获取两个 hits.customeDimenison.value 的正确函数？

SELECT
 Date
  ,COUNT(DISTINCT FULLVISITORID)
 , product.v2ProductCategory

  ,max(if(customDimensions.index=2, customDimensions.value,null))  as dest
  ,max(if(customDimensions.index=21, customDimensions.value,null))  as pax
 ,eCommerceAction.action_type
 ,product.v2ProductName

FROM `table` as t
  CROSS JOIN UNNEST(hits) AS hit
  CROSS JOIN UNNEST(hit.customDimensions) AS customDimensions
  CROSS JOIN UNNEST(hit.eCommerceAction) as eCommerceAction
  CROSS JOIN UNNEST(hit.product) AS product
GROUP BY 
      Date
      ,product.v2ProductCategory
    ,eCommerceAction.action_type
,product.v2ProductName

我得到的错误代码是错误：UNNEST 中引用的值必须是数组。 UNNEST 包含 STRUCT 类型的表达式

Answer 1

我可以用更简单的查询重现错误：

#standardSQL
SELECT DISTINCT hit.eCommerceAction.action_type 
FROM `73156703.ga_sessions_20170109` t
  , UNNEST(hits) hit
  , UNNEST(hit.customDimensions) customDimensions
  , UNNEST(hit.eCommerceAction) as eCommerceAction

这里的问题是eCommerceAction 不是REPEATED 记录，因此UNNEST 没有数组。

固定查询：

#standardSQL
SELECT DISTINCT hit.eCommerceAction.action_type 
FROM `ga_sessions_20170109`  t
  , UNNEST(hits) hit
  , UNNEST(hit.customDimensions) customDimensions