How do I INSERT columns with nested name syntax (ie. "item.description")? - google-bigquery

Question

I'm trying to merge two databases with the same schema on Google BigQuery.
I'm following the merge samples here: https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement
However, my tables have nested columns, ie "service.id" or "service.description"
My code so far is:
MERGE combined_table
USING table1
ON table1.id = combined_table.id
WHEN NOT MATCHED THEN
INSERT(id, service.id, service.description)
VALUES(id, service.id, service.description)
However, I get the error message: Syntax error: Expected ")" or "," but got ".", and a red squiggly underline under .id on the INSERT(...) line.
Here is a view of part of my table's schema:
[
{
"name": "id",
"type": "STRING"
},
{
"name": "service",
"type": "RECORD",
"fields": [
{
"name": "id",
"type": "STRING"
},
{
"name": "description",
"type": "STRING"
}
]
},
{
"name": "cost",
"type": "FLOAT"
}
...
]
How do I properly structure this INSERT(...) statement so that I can include the nested columns?

Answer 1

Syntax error: Expected ")" or "," but got "."
Looks like you are on the right direction, Note in the documentation how you need to insert value to a REPEATED column,
You need to define the structure to guide BigQuery what to expect, For example:
STRUCT<created DATE, comment STRING>
This is the full example from the documentation
MERGE dataset.DetailedInventory T
USING dataset.Inventory S
ON T.product = S.product
WHEN NOT MATCHED AND quantity < 20 THEN
INSERT(product, quantity, supply_constrained, comments)
-- insert values like this
VALUES(product, quantity, true, ARRAY<STRUCT<created DATE, comment STRING>>[(DATE('2016-01-01'), 'comment1')])
WHEN NOT MATCHED THEN
INSERT(product, quantity, supply_constrained)
VALUES(product, quantity, false)

Answer 2

I've found the answer.
It turns out when referencing the top level of a STRUCT, BigQuery references all of the nested columns as well. So if I wanted to INSERT service and all of it's sub-columns (service.id and service.description), I only have to include service in the INSERT(...) statement.
The following code worked:
...
WHEN NOT MATCHED THEN
INSERT(id, service)
VALUES(id, service)
This would merge all sub columns, including service.id and service.description.