Regarding a criteria.Please see my query

Question

In my table 'Posting' i have the columns
id_trade_ref        type
5V973781B           NEW
5V973781B           SET
5V973781B           REV
Criteria:
If the posting is booked having type SET and REV with identical 'id_trade_ref',
then display only 'NEW'
So I am using this in my where clause:
SQL Query
from posting p
where p.id_ref_type = '5V973781B '
and .type in ('NEW')
Because I know there are MULTIPLE identical id_ref_type, I will display NEW.
But suppose,there is only one record in the POSTING TABLE with type as REV.
id_trade_ref        type
5V973781B        REV
As there is only one record,REV,this needs to be displayed too.
How can I make this check in the where clause?
ie,If identical id_trade_ref,then display 'NEW'
   If single,then display that one only
   Do I use the CASE Select?
Can someone help?
Has anyone understood my query?

Answer 1

Well, you never give any hint about your business logic, so we can only provide low help.
Anyway, the following query gives the required resuld on your data sample...
TEST> CREATE TABLE monal
  2  (
  3  id_trade_ref     NUMBER,
  4  id_posting_ref   NUMBER,
  5  id_posting_type  CHAR(3 CHAR)
  6  );
Table created.
TEST> INSERT INTO monal VALUES (2231229, 11749444,'SET');
1 row created.
TEST> INSERT INTO monal VALUES (2231229, 11749446,'REV');
1 row created.
TEST> INSERT INTO monal VALUES (2231229, 11749448,'SET');
1 row created.
TEST> COMMIT;
Commit complete.
TEST> SELECT *
  2  FROM monal
  3  ORDER BY id_trade_ref, id_posting_ref;
ID_TRADE_REF ID_POSTING_REF ID_
     2231229       11749444 SET
     2231229       11749446 REV
     2231229       11749448 SET
TEST> SELECT *
  2  FROM monal up
  3  WHERE id_trade_ref IN (SELECT id_trade_ref
  4                     FROM monal
  5                     WHERE id_posting_type = 'SET'
  6                     GROUP BY id_trade_ref
  7                     HAVING COUNT(*) >1)
  8  AND id_posting_type = 'SET'
  9  AND id_posting_ref = (SELECT MAX(id_posting_ref)
10                     FROM monal
11                     WHERE id_trade_ref=up.id_trade_ref
12                     AND id_posting_type='SET')
13  ;
ID_TRADE_REF ID_POSTING_REF ID_
     2231229       11749448 SETYoann.