Need a query to get hihgest

Question

Hi all,
I am having data like this
INSPRESULTDATA_ID     CREATE_DATE
1367               7.5.28
1368               7.5.28
1369               7.5.28
1373               7.5.29
By using following query, i will get
select INSPRESULTDATA_ID, CREATE_DATE
from
select rank() over (order by CREATE_DATE desc) rank1, INSPRESULTDATA_ID, CREATE_DATE
from
(select distinct(CREATE_DATE), INSPRESULTDATA_ID from INSPRESULTDATA1 A WHERE A.CARNUMBER='FinalTest')
where rank1 <2
1373               7.5.29
if suppose data is like this
INSPRESULTDATA_ID     CREATE_DATE
1367               7.5.28
1368               7.5.28
1369               7.5.28
------------------------------with-----ordery by condition changed here----
select INSPRESULTDATA_ID, CREATE_DATE
from
select rank() over (order by CREATE_DATE, INSPRESULTDATA_ID desc) rank1, INSPRESULTDATA_ID, CREATE_DATE
from
(select distinct(CREATE_DATE), INSPRESULTDATA_ID from INSPRESULTDATA1 A WHERE A.CARNUMBER='FinalTest')
where rank1 <2
-----------i will get-------
1369               7.5.28
My question is.....
I dont know, how data will be present in the table, sometimes like first condition
and sometimes like second condition, i want to write a query
If on same date, many records are there, i have to fetch highest based on INSPRESULTDATA_ID value.
The problem is, i dont know how data will be present in table and i have to write one query to suitable for two conditions. Any help is appreciated.
Thanks in advance,
Pal

Answer 1

The simplest are allways the best solutions!
I omitted some details but I hope the sense of this could come out as well.
SQL> create table inspresultdata1 as (
  2     select a.table_name as inspresultdata_id,a.last_analyzed as create_date
  3     from dba_tables a
  4     where a.owner = 'SYS'
  5             and a.last_analyzed is not null
  6  )
  7  /
Table created.
SQL>
SQL> select inspresultdata_id, create_date
  2  from (
  3     select rownum rn, inspresultdata_id, create_date
  4     from (
  5             select inspresultdata_id, create_date
  6             from inspresultdata1 a
  7             order by create_date desc, inspresultdata_id desc
  8     )
  9  ) b
10  where b.rn < 2
11  /
INSPRESULTDATA_ID              CREATE_DA
IND$                           28-MAY-07
Execution Plan
Plan hash value: 1278622425
| Id  | Operation             | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT      |                 |   656 | 25584 |     3   (0)| 00:00:01 |
|*  1 |  VIEW                 |                 |   656 | 25584 |     3   (0)| 00:00:01 |
|   2 |   COUNT               |                 |       |       |            |          |
|   3 |    VIEW               |                 |   656 | 17056 |     3   (0)| 00:00:01 |
|   4 |     SORT ORDER BY     |                 |   656 | 17056 |     3   (0)| 00:00:01 |
|   5 |      TABLE ACCESS FULL| INSPRESULTDATA1 |   656 | 17056 |     3   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - filter("B"."RN"<2)
Note
   - dynamic sampling used for this statement
Statistics
         51  recursive calls
          0  db block gets
         21  consistent gets
          3  physical reads
          0  redo size
        276  bytes sent via SQL*Net to client
        235  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
          1  rows processed
SQL>
SQL> select inspresultdata_id, create_date
  2    from (
  3           select row_number() over (order by create_date desc, inspresultdata_id desc) rn,
  4                  inspresultdata_id, create_date
  5            from inspresultdata1 a
  6         )
  7  where rn = 1
  8  /
INSPRESULTDATA_ID              CREATE_DA
IND$                           28-MAY-07
Execution Plan
Plan hash value: 626911456
| Id  | Operation                | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT         |                 |   656 | 25584 |     4  (25)| 00:00:01 |
|*  1 |  VIEW                    |                 |   656 | 25584 |     4  (25)| 00:00:01 |
|*  2 |   WINDOW SORT PUSHED RANK|                 |   656 | 17056 |     4  (25)| 00:00:01 |
|   3 |    TABLE ACCESS FULL     | INSPRESULTDATA1 |   656 | 17056 |     3   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - filter("RN"=1)
   2 - filter(ROW_NUMBER() OVER ( ORDER BY INTERNAL_FUNCTION("CREATE_DATE") DESC
              ,INTERNAL_FUNCTION("INSPRESULTDATA_ID") DESC )<=1)
Note
   - dynamic sampling used for this statement
Statistics
          7  recursive calls
          0  db block gets
         17  consistent gets
          0  physical reads
          0  redo size
        277  bytes sent via SQL*Net to client
        235  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
          1  rows processed
SQL>
SQL> drop table inspresultdata1 purge
  2  /
Table dropped.Bye Alessandro
Message was edited by:
Alessandro Rossi