Hi All, I have a table called
vehicle_duty_cycle_summary vehicle_master_id | starting_odometer | ending_odometer | login_time | logout_time -------------------+-------------------+-----------------+----------------------------+---------------------------- 4 | 53379.00 | 53504.00 | 2006-12-19 16:19:16.584547 | 2006-12-20 07:12:57.716907 4 | 51310.00 | 51457.00 | 2006-12-05 16:04:51.585441 | 2006-12-06 07:18:10.251535 4 | 42411.00 | 42411.00 | 2006-09-14 16:03:49.541442 | 2006-09-15 08:24:41.308339 4 | 54012.00 | 54146.00 | 2006-12-25 16:14:31.313728 | 2006-12-26 07:05:55.82487 4 | 43071.00 | 43181.00 | 2006-09-21 11:24:43.466766 | 2006-09-22 07:10:09.362792 4 | 51208.00 | 51305.00 | 2006-12-04 16:14:14.600105 | 2006-12-05 08:03:38.139832 4 | 50235.00 | 50370.00 | 2006-11-27 15:55:48.866925 | 2006-11-28 07:27:25.898991 4 | 53231.00 | 53362.00 | 2006-12-18 16:06:42.764133 | 2006-12-19 07:06:03.450072 4 | 52656.00 | 52818.00 | 2006-12-13 16:03:47.189303 | 2006-12-14 07:59:11.463733 4 | 50801.00 | 50880.00 | 2006-12-02 16:03:55.666321 | 2006-12-03 06:53:21.433746 9 | 85360.00 | 85493.00 | 2007-06-10 07:17:12.330974 | 2007-06-10 22:11:04.422656 9 | 78009.00 | 78042.00 | 2007-03-12 17:53:18.794001 | 2007-03-12 20:42:39.439647 9 | 84529.00 | 84679.00 | 2007-06-01 06:42:09.306306 | 2007-06-01 20:35:54.317172 9 | 78058.00 | 78149.00 | 2007-03-13 10:08:48.696709 | 2007-03-13 21:50:31.136412 9 | 86506.00 | 86595.00 | 2007-06-21 09:28:40.504082 | 2007-06-21 23:15:41.862292 9 | 78155.00 | 78239.00 | 2007-03-14 09:32:58.512817 | 2007-03-14 20:58:24.36362 9 | 84894.00 | 85012.00 | 2007-06-04 07:59:00.896969 | 2007-06-04 18:42:13.791974 9 | 78435.00 | 78494.00 | 2007-03-16 07:48:23.626402 | 2007-03-16 21:39:09.479043 9 | 83992.00 | 84045.00 | 2007-05-25 07:25:20.462928 | 2007-05-25 21:23:43.697577 9 | 78506.00 | 78595.00 | 2007-03-17 08:01:06.003564 | 2007-03-17 19:48:32.383689 9 | 85493.00 | 85640.00 | 2007-06-11 06:58:03.052538 | 2007-06-11 22:56:13.134053 9 | 78279.00 | 78395.00 | 2007-03-15 08:00:58.198265 | 2007-03-15 21:39:00.052173 I would like to compute the following on this table. Idle time of vehicel=(ending_odometer reading of the previous day - starting_odometer reading of the present day) for every vehicle can anybody help me this issue. Thanks in advance. Trilok __________________________________________________________ Sent from Yahoo! Mail - a smarter inbox http://uk.mail.yahoo.com ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend