How do I get all timestamps associated with an ID and aggregate it them into total time elapsed?

I have a sample table:

id   timestamp 
1    2020-02-03T19:25:41.961Z   
1    2020-02-03T19:25:42.000Z   
1    2020-02-03T19:26:33.147Z   
2    2020-02-03T20:21:29.684Z
2    2020-02-03T20:21:29.705Z

In BigQuery, I want to group all of the columns with the same ID together, and then get the total elapsed time between all of the timestamp cols for that ID.

Answer

You can use timestamp_diff():

select id, timestamp_diff(max(timestamp), min(timestamp), second) as diff_seconds
from t
group by id;