BigQuery Unnest an Array - Getting dupliates

Question

Im working on GCP Billing queries in BQ. But while extracting array with the cost I'm getting wrong values like unnest returns array elements in row format. So if I have 2 elements in an array for a single row then I'll get 2 rows.

EG:

Actual Array:

SELECT

TO_JSON_STRING(labels), cost

FROM

billing_export.gcp_billing_export

WHERE

_PARTITIONTIME >= "2018-08-01 00:00:00"

AND _PARTITIONTIME < "2018-09-01 00:00:00"

AND billing_account_id = "xxx-62378F-xxx"

AND TO_JSON_STRING(labels) = '[{"key":"application","value":"scaled-server"},{"key":"department","value":"hrd"}]'

and cost> 0 limit 10

with Unnest:

with cte as (SELECT

labels, cost

FROM

billing_export.gcp_billing_export

WHERE

_PARTITIONTIME >= "2018-08-01 00:00:00"

AND _PARTITIONTIME < "2018-09-01 00:00:00"

AND billing_account_id = "xxx-62378F-xxxx"

AND TO_JSON_STRING(labels) = '[{"key":"application","value":"scaled-server"},{"key":"department","value":"hrd"}]'

and cost> 0

limit 10 )

select labels,cost from cte ,

UNNEST(labels) AS la

Question:

I don't want duplicate cost value, Can anyone help me with this query?

Answer 1

instead of

SELECT labels,cost from cte ,
UNNEST(labels) AS la   

try

SELECT la, cost from cte ,
UNNEST(labels) AS la   

Update

SELECT 
  ARRAY(
    SELECT AS STRUCT 
      JSON_EXTRACT_SCALAR(kv, '$.key') key, 
      JSON_EXTRACT_SCALAR(kv, '$.value') value 
    FROM UNNEST(SPLIT(labels, '},{')) kv_temp, 
    UNNEST([CONCAT('{', REGEXP_REPLACE(kv_temp, r'^\[{|}]$', ''), '}')]) kv
  ) labels,
  cost
FROM cte