Select wich returns the shortest time

Question

Hi,
I don't know how to do a select. I'm goig to explain what I want to get to see wheter somebody can help.
I've a select that returns the following columns (table t):
handle_id, logon_id, object_name
I've another table with the following columns (table t0):
time0, handle_id, logon_id, object_name, source, eventid
If I do this select:
select t0.time0, t0.source, t0.eventid
from t, t0
where t.handle_id = t0.handle_id and t.logon_id = t0.logon_id and t.object_name = t0.object_name
It returns me several records with the same condition (handle_id, logon_id, object_name) because, obviously, I've repeated recors with the same conditions but with diferent time0.
I would like to get only one record for each condtion with the shortest time0.
How can I do it?
I've tried with distinct but it isn't what I want.
Thanks in advance.
Regards.

Answer 1

select  *
  from  (
         select  t0.time0, t0.source, t0.eventid........ , t0.accesses,
                 row_number() over(partition by t0.handle_id,t0.logon_id,t0.object_name order by t0.time0) rn
           from  t,
                 t0
           where t.handle_id = t0.handle_id
             and t.logon_id = t0.logon_id
             and t.object_name = t0.object_name
  where rn = 1
/If there can be more than one row with "shortest time0" for same handle, logon_id, object_name the above query will return olny one of such rows. If you want to get all such rows use:
select  *
  from  (
         select  t0.time0, t0.source, t0.eventid........ , t0.accesses,
                 dense_rank() over(partition by t0.handle_id,t0.logon_id,t0.object_name order by t0.time0) rn
           from  t,
                 t0
           where t.handle_id = t0.handle_id
             and t.logon_id = t0.logon_id
             and t.object_name = t0.object_name
  where rn = 1
/SY.