Retriving multiple rows from the same table

Question

Hi all,
I have a table consisting of an id column as well as a start and end date.
What I want to do is select the difference between start and end time for different id's.
For example select (endtime where id = 1 - starttime where id = 2).
Is this possible to do using a single select statement?
Thanks ppl

Answer 1

OK, so you want every combination of dropped_id 500 with dropped_id 1000? For example:
WITH test_data as (SELECT 500 dropped_id, TO_DATE('13/05/2009', 'DD/MM/YYYY') insert_date, TO_DATE('12/05/2009 12:00:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('12/05/2009 12:30:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL UNION ALL
SELECT 500, TO_DATE('12/05/2009', 'DD/MM/YYYY'),  TO_DATE('11/05/2009 12:04:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('11/05/2009 12:41:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL UNION ALL
SELECT 500,TO_DATE('11/05/2009', 'DD/MM/YYYY'), TO_DATE('10/05/2009 12:18:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('10/05/2009 12:59:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL UNION ALL
SELECT 1000,TO_DATE('13/05/2009', 'DD/MM/YYYY'), TO_DATE('12/05/2009 12:30:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('12/05/2009 13:30:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL UNION ALL
SELECT 1000,TO_DATE('12/05/2009', 'DD/MM/YYYY'), TO_DATE('11/05/2009 12:41:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('11/05/2009 14:30:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL UNION ALL
SELECT 1000,TO_DATE('11/05/2009', 'DD/MM/YYYY'), TO_DATE('10/05/2009 12:19:00', 'DD/MM/YYYY HH24:MI:SS') starttime, TO_DATE('10/05/2009 13:30:00', 'DD/MM/YYYY HH24:MI:SS') endtime FROM DUAL)
-- end test data
SELECT tab1.insert_date insert_date1, tab2.insert_date insert_date2, tab1.dropped_id dropped_id1,   tab2.dropped_id dropped_id2, ROUND(tab2.endtime -  tab1.starttime,2) time_diff
   FROM test_data tab1
CROSS JOIN test_data tab2
WHERE tab1.dropped_id = 500
    AND tab2.dropped_id = 1000;
INSERT_DA INSERT_DA DROPPED_ID1 DROPPED_ID2  TIME_DIFF
13-MAY-09 13-MAY-09         500        1000        .06
12-MAY-09 13-MAY-09         500        1000       1.06
11-MAY-09 13-MAY-09         500        1000       2.05
13-MAY-09 12-MAY-09         500        1000        -.9
12-MAY-09 12-MAY-09         500        1000         .1
11-MAY-09 12-MAY-09         500        1000       1.09
13-MAY-09 11-MAY-09         500        1000      -1.94
12-MAY-09 11-MAY-09         500        1000       -.94
11-MAY-09 11-MAY-09         500        1000        .05
9 rows selected.