I'm a bit stuck on how can do this so hoping someone can point me in the right direction.
I have this simple query:
SELECT acchl.is_current,
acchl.aircraft_registration_number,
acchl.aircraft_transponder_code
FROM fleets.aircraft_all_history_latest acchl
WHERE acchl.is_current = true
Which I then want to use the results from this query to find all the duplicate aircraft transponder codes along with the aircraft registration numbers with something like a self join to fetch the actual rows that may have duplicate values using something like this:
select s.id, s.col_maybe_dups
from sometab s
join (select col_maybe_dups as cd
from sometab
group by cd
having count(*) > 1) x
on x.cd = s.col_maybe_dups;
CodePudding user response:
Looks good!
You could WITH
it too...
WITH data as (
SELECT acchl.is_current,
acchl.aircraft_registration_number,
acchl.aircraft_transponder_code
FROM fleets.aircraft_all_history_latest acchl
WHERE acchl.is_current
)
select * from data
where aircraft_transponder_code in
(select aircraft_transponder_code
from data
group by 1
having count(*) > 1
)