Google BigQuery - Updating a nested repeated field

Question

I am trying to update the hits.page.pagePath field in the Google Analytics export in BigQuery, however i\'m unable to unnest the field using the method outlined in the docum

Answer 1

This should help get you started. You need to include everything else from hits in order to perform the update, including the nested page.

UPDATE `you_dataset.tablename`
SET hits = ARRAY(
  SELECT AS STRUCT * REPLACE (
    (SELECT AS STRUCT page.* REPLACE ('foo' AS pagePath)) AS page
  )
  FROM UNNEST(hits) as pagePath
)
WHERE fullVisitorID like "%1%"

Answer 2

Below is for BigQuery Standard SQL

UPDATE `project-name.datasetId.ga_sessions_yyyymmdd`
SET hits =  ARRAY(
    SELECT AS STRUCT * REPLACE(
      (SELECT AS STRUCT * 
        REPLACE('Your New pagePath' AS pagePath) 
        FROM UNNEST([page])
      ) AS page) 
    FROM UNNEST(hits)
  ) 
WHERE fullVisitorID like "%1%"    

As you can see in above example you would replace pagePath with string 'Your New pagePath'
Of course in reality you would want to have some logic here - so replace that part to whatever logic you need - like for example you would need to UPPER whole string - you would use something like below

        REPLACE(UPPER(pagePath) AS pagePath)