How to get data from Json to multiple column PostgreSQL

I want to extract many objects (not all object) in JSON but don’t want to type for every single thing like this:

Select *,  
metrics::json ->> 'spend',
metrics::json ->> 'impressions',
metrics::json ->> 'clicks'
from t1

Here my DEMO show real data and case, how to extract to multiple columns and cast it to exact data type (float, integer)

I refer this question, can I use json_to_record for this or other method and how?

Answer

You can just specify the columns you want in the return structure. So if you’re only interested in “spend” and “impressions”, you can do

SELECT x.*
FROM t1, json_to_record(t1.metrics) 
AS x(spend numeric, impressions int);