Null handling with greatest function

Question

Hi , My oracle version is 10.2 and I am trying to get max value from three dates.
col1,                col2,               col3                                max_date
*12/4/2007 12/5/2009 7:14:57 PM*
col1 value is null . so when I use below sql
select greatest(NVL(col1,col2)) from temp_greatest where rec_id=366957734, I got value 12/4/2007
I want to get max date from col1,col2 and col3, even though col1 is null.
I have couple of rows with col2 acnd col3 as null values.
How to get the max values.. any help appreciate
Thanks

Answer 1

Here you go.
CREATE TABLE SSPTRIG.TEMP_GREATEST_1207
COl1_DATE DATE,
col2_DATE DATE,
col3_DATE DATE,
max_date DATE
SET DEFINE OFF;
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(NULL, TO_DATE('12/04/2007 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), TO_DATE('12/05/2009 19:14:57', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/03/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 05:26:08', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/03/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 05:26:07', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/04/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 06:10:55', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('08/09/2005 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), TO_DATE('12/05/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), TO_DATE('12/05/2009 21:01:12', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/04/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 05:44:37', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/04/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 05:44:33', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/04/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 06:41:14', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('12/04/2009 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 05:44:31', 'MM/DD/YYYY HH24:MI:SS'));
Insert into TEMP_GREATEST_1207
(COL1_DATE,COL2_DATE,COL3_DATE)
Values
(TO_DATE('10/08/2008 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), NULL, TO_DATE('12/05/2009 21:02:38', 'MM/DD/YYYY HH24:MI:SS'));
COMMIT;
i NEED TO POPULATE MAX DATE INTO MAX_DATE COLUMN IN TEMP_GRATEST_1207.
THANKS.