How to get time diff between two rows ???

Question

I need to calculate the time difference of rows based on a column's value how do i do that ??
say i have a table statistics
id timing
100 10-JAN-07 09.52.10.000000 AM
200 10-JAN-07 09.59.10.000000 AM
300 10-JAN-07 09.59.30.000000 AM
I want to get the time taken by 200 ie timing of 200 - timing of 100
how do i get that .
similarly for id 300 and so on .
regards
Shub

Answer 1

SQL> create table mytable
  2  as
  3  select 100 id, to_timestamp('10-JAN-07 09.52.10.000000 AM','DD-MON-RR HH:MI:SS:FF AM') timing from dual union all
  4  select 200 , to_timestamp('10-JAN-07 09.59.10.000000 AM','DD-MON-RR HH:MI:SS:FF AM') from dual union all
  5  select 300 , to_timestamp('10-JAN-07 09.59.30.000000 AM','DD-MON-RR HH:MI:SS:FF AM') from dual
  6  /
Tabel is aangemaakt.
SQL> select id
  2       , timing
  3       , timing - lag(timing) over (order by timing) diff
  4    from mytable
  5  /
   ID TIMING                         DIFF
  100 10-01-07 09:52:10,000000000
  200 10-01-07 09:59:10,000000000    +000000000 00:07:00.000000000
  300 10-01-07 09:59:30,000000000    +000000000 00:00:20.000000000
3 rijen zijn geselecteerd.Regards,
Rob.