Query to check that which sequence is missing

Question

Hi all,
hope all of you are fine.
plz guide me in writing auery so that i can check that which sequence is missing...
for example i have a column in which i generated the auto no with sequence
like 3501,3502,3503....................
later user can delete the record....
Now i want to check that which of the sequence is breaked like
3501,3502,3504.........now 3503 is missing........I want to check all that are missing from sequence.......
Hope you understand what i want to say
thanks in advance
Shayan
[email protected]

Answer 1

And a slight variantion on maaher's last solution, applicable when you are not on 10g yet:
SQL> create table mytable
  2  as
  3  select 1 id from dual union all
  4  select 2 from dual union all
  5  select 4 from dual union all
  6  select 5 from dual union all
  7  select 8 from dual union all
  8  select 9 from dual union all
  9  select 10 from dual union all
10  select 13 from dual
11  /
Tabel is aangemaakt.
SQL> select level id from (select max(id) maxid from mytable) connect by level <= maxid
  2  minus
  3  select id from mytable
  4  /
                                    ID
                                     3
                                     6
                                     7
                                    11
                                    12
5 rijen zijn geselecteerd.Regards,
Rob.