Update nested field in BigQuery table

Question

I am trying to perform what, you would think, is a trivial operation in BigQuery; I am trying to update a nested field in a BigQuery table that is the result of a 360 export

Answer 1

hits is an array, so you need to use an array subquery to assign to it. It would look something like this:

#standardSQL
UPDATE `dataset_name`.`ga_sessions_20170705`
SET hits =
  ARRAY(
    SELECT AS STRUCT * REPLACE(
      (SELECT AS STRUCT eventInfo.* REPLACE('some string' AS eventLabel)) AS eventInfo)
    FROM UNNEST(hits)
  )
WHERE TRUE;