SQL Concat and convert date to MM/YYYY - sql

Question

Newbie here. Thanking you in advance for your help!
I have the following code to count unique records based on 3 data elements:
count(distinct concat(a.emp_nbr, b.acct_nbr, c.event_dt))
The event_dt is stored in the db as [DATE].
the issue is that i don't want to EXCLUDE 'DD' in the concat match statement. I want to match based on the MM/YYYY only. I believe the answer is to convert the [DATE] to MM/YYYY.
Ultimately i want to count distinct records based on emp_nbr, acct_nbr and mm/yyyy of event_dt.
Thanks!
MODIFIED
here is the query:
select distinct
B.emp_nbr, A.cust_nbr, E.cntry_enti_nbr, A.event_dt,
count(distinct concat(B.emp_nbr, E.cntry_enti_nbr, A.event_dt))
from customer A
left join user_profile B on A.owner_ID = B.owner_ID
left join account_owner E on A.cust_nbr = E.cust_nbr
where CAST(A.ramp_dt AS date format 'MM/DD/YYYY') between '01/01/2020' and '08/31/2020'
group by 1,2,3,4
Here's a sample of the results that are returned:
ln...emp_nbr.....cust_nbr.....ctry_enti_nbr event_dt......'Unique Identifier'
1....123.........87543290......488807........5/15/2020.........1
2....123.........62524497......488807........2/28/2020.........1 **
3....123.........62524497......488807........2/26/2020.........1 **
4....789.........62524497......488807........2/26/2020.........1
5....876.........62524497......488807........2/26/2020.........1
Line 2 or 3 should NOT be flagged as '1' (unique)
EDIT: changed code based on dnoeth's reco to add the count(*) OVER (PARTITION):
select distinct
B.emp_nbr, A.cust_nbr, E.cntry_enti_nbr, A.event_dt,
to_char(A.event_dt, 'YYYYMM') as Event_Month,
case when COUNT(*) OVER (PARTITION BY B.emp_nbr, A.cntry_enti_nbr, Event_Month)
= 1 then 1 else 0 end as Unique_Monthly_Event
from customer A
left join user_profile B on A.owner_ID = B.owner_ID
left join account_owner E on A.cust_nbr = E.cust_nbr
where CAST(A.event_dt AS date format 'MM/DD/YYYY') between '01/01/2020' and '08/31/2020'
group by 1,2,3,4
works fine for the previous case, however in another case it shows all ZERO for unique:
ln...emp_nbr.....cust_nbr.....ctry_enti_nbr event_dt......'Unique Identifier'
1....123.........78473466......863429........5/31/2020.........0
2....123.........78473466......863429........5/29/2020.........0
3....123.........78473466......863429........5/5/2020..........0
I would like to see ONE record with a unique identifier of "1"

Answer 1

Line 2 or 3 should NOT be flagged as '1' (unique)
... because there's more than one row per emp_nbr/cust_nbr/ctry_enti_nbr?
Then you need a simple Group Count:
select
B.emp_nbr, A.cust_nbr, E.cntry_enti_nbr, A.event_dt,
-- I would like to see ONE record with a unique identifier of "1"
-- this returns the row with the latest event date
case
when row_number()
over (partition by B.emp_nbr, A.cust_nbr, E.cntry_enti_nbr
order by event_dt desc) = 1
then 1
else 0
end
from customer A
left join user_profile B on A.owner_ID = B.owner_ID
left join account_owner E on A.cust_nbr = E.cust_nbr
where CAST(A.ramp_dt AS date format 'MM/DD/YYYY') between '01/01/2020' and '08/31/2020'
group by 1,2,3,4

Answer 2

You can simply use EXTRACT() function to extract year and month from the date. For example:
SELECT COUNT(DISTINCT CONCAT(a.emp_nbr, b.acct_nbr, EXTRACT(YEAR FROM c.event_dt), EXTRACT(MONTH FROM c.event_dt)))
FROM ...

Answer 3

You can use to_char(). Something like this:
count(distinct concat(a.emp_nbr, '|', b.acct_nbr, '|', to_char(c.event_dt, 'YYYYMM'))
or more commonly:
count(distinct a.emp_nbr || '|' || b.acct_nbr || '|' || to_char(c.event_dt, 'YYYYMM')
Note that this also puts a delimiter between
Your query looks off. I think you just want:
select A.cust_nbr, E.cntry_enti_nbr, to_char(c.event_dt, 'YYYYMM'),
count(*)
from customer A left join
user_profile B
on A.owner_ID = B.owner_ID left join
account_owner E
on A.cust_nbr = E.cust_nbr
where CAST(A.ramp_dt AS date format 'MM/DD/YYYY') between '01/01/2020' and '08/31/2020'
group by A.cust_nbr, E.cntry_enti_nbr, to_char(c.event_dt, 'YYYYMM');