Updating a nested field in a BigQuery table
I'm trying to accomplish what you 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.
Here is my request:
#standardSQL
UPDATE `dataset_name`.`ga_sessions_20170705`
SET hits.eventInfo.eventLabel = 'some string'
WHERE TRUE
But I am getting this error message:
Error: Cannot access field eventInfo on a value with type ARRAY<STRUCT<item STRUCT<transactionId INT64, currencyCode STRING>, isEntrance BOOL, minute INT64, ...>> at [3:10]
How do I update this subfield?
+3
source to share
1 answer
hits
is an array, so you need to use an array subquery to assign it. It will 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;
+2
source to share