PostgresSql Query

I want to get the activity_id of the 1st "email" activity that happened in between the "completed_order" activity in a different column. tried this below code but instead of getting the id of the first "email" activity, I am getting the id of "completed_order" activity.

SELECT     activity_id,      customer ,      activity,     ts,    case       when        activity = 'completed_order' and lead(activity) over (partition by customer order by ts) ='email'      then              activity_id    end as cndn    from activity_stream   where customer in (     select customer where customer = 'Lehmanns Marktstand'   )   order by ts  

This should be my Desired Result

https://stackoverflow.com/questions/67260653/postgressql-query April 26, 2021 at 11:56AM