Multiple max values in a query

Question

I know the title does not sound very descriptive, but it is the best I could think of:

I have this table

ID     BDATE      VALUE
28911  14/4/2009  44820
2         


        

Answer 1

you can use the MAX...KEEP(DENSE_RANK FIRST...) construct:

SQL> SELECT ID,
  2         MAX(bdate) bdate,
  3         MAX(VALUE) KEEP(DENSE_RANK FIRST ORDER BY bdate DESC) VALUE 
  4   FROM DATA
  5  GROUP BY ID;

        ID BDATE            VALUE
---------- ----------- ----------
     28911 24/04/2009  7749594,67
     38537 22/04/2009    81098692
     38605 23/04/2009     6936575

This will be as efficient as the analytics method suggested by Majkel (no self-join, a single pass on the data)

Answer 2

We can use multiply columns in an IN clause:

select id, bdate, value 
from myview 
where (id, bdate) in
    (select id, max(bdate)
     from myview group by id)
/

Answer 3

select a.* from myview a, (select id, max(bdate) from myview group by id) b
where a.id = b.id and a.bdate = b.bdate

Answer 4

You can use an INNER JOIN to filter out only the maximum rows:

select t.*
from YourTable t
inner join (
     select id, max(bdate) as maxbdate
     from YourTable
     group by id
) filter
    on t.id = filter.id
    and t.bdate = filter.maxbdate

This prints:

id     bdate       value
38605  2009-04-23  6936575
38537  2009-04-22  81098692
28911  2009-04-24  7749594.67

Note that this will return multiple rows for an id which has multiple values with the same bdate.

Answer 5

SELECT id, bdate, value FROM myview
 WHERE (id, bdate) IN (SELECT id, MAX(bdate) FROM myview GROUP BY id)

(untested... I don't have Oracle available right now...)

Answer 6

You can use analytics:

select 
      id, bdate, value 
    from
      (
        select
          id, bdate, value, max( bdate ) over ( partition by id ) max_bdate
        from
          myview
      )
    where
      bdate = max_bdate