Sequence based on a Group

Question

Hi,
I've got a table for example with following entries:
Col1, Col2
A 1
A 2
A 3
B 1
B 2
C 1
C 2
and I need an ID group based like
ID Col1 Col2
1 A 1
1 A 2
1 A 3
2 B 1
2 B 2
3 C 1
3 C 2
cheers,
Bernhard
Edited by: boffman on 17.02.2010 05:59

Answer 1

You can use the analytic function row_number, I would post a link to the documentation reference, but the manuals have been down so long I think people at Oracle have stopped using them as well as everyone else.
SQL> with the_data as
  2      (
  3      select 'A' a, 1 b from dual union all
  4      select 'A', 2 from dual union all
  5      select 'A', 3 from dual union all
  6      select 'B', 1 from dual union all
  7      select 'B', 2 from dual union all
  8      select 'C', 1 from dual union all
  9      select 'C', 2 from dual
10      )
11  select
12      a, b,
13      row_number () over (partition by a order by b) seq
14  from the_data;
A          B        SEQ
A          1          1
A          2          2
A          3          3
B          1          1
B          2          2
C          1          1
C          2          2
7 rows selected.