How to find a value in a column after I’ve used array_agg and struct?

After using the following code in my database, I got the following results:

select USERID, 
  array_agg(struct(ORDER_TIME, DELIVERY_TIME, PLATFORM) order by ORDER_TIME) STATS
from `project.dataset.table`
group by USERID 
having count(1) > 1
order by USERID

USERID	STATS.ORDER_TIME	STATS.DELIVERY_TIME	STATS.PLATFORM
011	2021-01-09 11:14:18	2021-01-09 11:44:01	mobile
	2021-02-12 16:15:51	2021-02-12 17:16:51	desktop
	2021-03-30 17:23:45	2021-02-12 17:16:51	desktop
033	2021-01-01 12:30:14	2021-01-01 13:30:00	mobile
	2021-04-16 23:00:45	2021-04-16 23:45:40	mobile
040	2021-02-18 19:22:55	2021-02-18 20:00:05	mobile
	2021-05-06 09:12:13	2021-05-06 10:00:10 ​	desktop

However, I only need those registers which contains both mobile AND desktop. So I need something like this, a result where there is no data for the USERID 040, because they only ordered on a mobile phone:

USERID	STATS.ORDER_TIME	STATS.DELIVERY_TIME	STATS.PLATFORM
011	2021-01-09 11:14:18	2021-01-09 11:44:01	mobile
	2021-02-12 16:15:51	2021-02-12 17:16:51	desktop
	2021-03-30 17:23:45	2021-02-12 17:16:51	desktop
033	2021-01-01 12:30:14	2021-01-01 13:30:00	mobile
	2021-05-06 09:12:13	2021-05-06 10:00:10 ​	desktop

How can I possibly do that? Thank you very much!

Answer

The “simplest” way is to add few more conditions into having clause

select USERID, array_agg(struct(ORDER_TIME, DELIVERY_TIME, PLATFORM) order by ORDER_TIME) STATS
from `project.dataset.table`
group by USERID 
having count(1) > 1
and 'mobile' in unnest(array_agg(PLATFORM))
and 'desktop' in unnest(array_agg(PLATFORM))
order by USERID     

if applied to sample data in your question – output is

In cases when you have more such entries to compare with – you can use below version to avoid repeating similar line of code

select USERID, array_agg(struct(ORDER_TIME, DELIVERY_TIME, PLATFORM) order by ORDER_TIME) STATS
from `project.dataset.table`
group by USERID 
having count(1) > 1
and array_length(array_agg(distinct if(PLATFORM in ('mobile', 'desktop'), PLATFORM, null))) = 2
order by USERID