DECODE function in Oracle gives duplicate data

Question

Hi,
I want to retrieve distinct result using decode function and given below are the queries for that.
SELECT DISTINCT O.*, DECODE(TA,'AP',AMT,'AC1',AMT,'AC2',AMT,'AC3',AMT,'AC4',AMT,NULL) AS CA,
DECODE(TA,'AD1',AMT,NULL) AS DA FROM HT O, HIS H, V_CV
WHERE O.HID=H.HID AND H.HTYP='TRN' AND O.HID = V.HID AND V.CID = '5' ORDER BY CA ASC;
which gives me
HID   TA      PT     AMT     CA         DA
2     A     V     4.1     4.1     null
3     C     V     14.02 14.02     null
1     D     V 5.1     null          5.1
4     D     V     6.21     null      6.21
which is correct but i want to do sorting on two different column which do not exit in the database and they are dynamic.So i Modified the Query but i am getting duplicate results
SELECT DISTINCT O.*,
DECODE(o.TA,cr.TA,o.AMT,NULL) AS CA,
DECODE(o.TA,de.TA,o.AMT,NULL) AS DA
FROM HT O,
HIS H,
V_CV,
(select TA from RTD where Ttype= 'C') cr,
(select TA from RTD where Ttype= 'D') de
WHERE
O.HID=H.HID
AND H.HTYP='TRN'
AND O.HID = V.HID
AND V.CID = '5'
ORDER BY CA ASC
which gives me
HID   TA      PT     AMT     CA         DA
2     A     V     4.1     4.1     null
3     C     V     14.02 14.02     null
3     C     V     14.02 null      null
1     D     V 5.1     null          5.1
1     D     V 5.1     null          null
4     D     V     6.21     null      6.21
2     A     V     4.1     null     null
which is obviously giving HID 2,3,1 as duplicate value since DECODE select a value and compares with all item where i want only single comparison.
Any help regarding this would be appreciated.
Edited by: Pawanchoure on Jul 5, 2011 7:14 AM

Answer 1

Why don't you have any join conditions specified for your two inline views cr and de?
If you want help with a query you should post DDL and inserts statements to create enough test data for someone to produce the set of results that you are looking for.
HTH -- Mark D Powell --