Please help oracle sql counts question

Question

Hi,
I am trying to get some counts on a client list where l count those clients who are getting the program
2353335 ONLY (which may be none of the cases in the example below but this is an obviously smaller subset of these data).
How can I count all the client ids where program = 2353335 but not where program = 2340845 or program =2353340?
Thanks in advance
Client_id     Program
260     2340845
260     2353340
510     2353340
510     2353335
510     2340845
520     2340845
520     2353340
525     2340845
525     2353335
765     2353340
1260     2340845
1260     2353335
1595     2353340
1595     2340845
1615     2340845
1835     2353340
1840     2353340
1840     2353335
1840     2340845
1845     2353335
1845     2340845

Answer 1

Hi,
if you want to select clients that only have program 2353335 and no other, the query below would help:
select client_id
from mytab m
where program = 2353335
and not exists (select 1 from mytab where client_id = m.client_id and program != 2353335);Just replace select client_id with select count(*) if you want just to count rows.
Best regards,
Nikolay
Edited by: Nikolay Savvinov on Jan 26, 2012 11:24 PM