NEED SQL QUERY writing help

Question

oracle 10g.
os : linux
table data appears like this
SQL> select * from test_grp;
COL1 COL2
aaa 111
aaa 444
aaa 222
bbb 333
bbb 555
SQL> select * from test_grp order by 2;
COL1 COL2
aaa 111
aaa 222
bbb 333
aaa 444
bbb 555
As per my application requirement I need to seggerage the data as
follows
aaa (2) ie --- 111,222
bbb(1) is --- 333
aaa(1) is --- 444
bbb(1) is -- 555
I am not able to frame this. Any help ?

Answer 1

SQL> create table test_grp
  2  as
  3  select 'aaa' col1, 111 col2 from dual union all
  4  select 'aaa', 444 from dual union all
  5  select 'aaa', 222 from dual union all
  6  select 'bbb', 333 from dual union all
  7  select 'bbb', 555 from dual
  8  /
Tabel is aangemaakt.
SQL> select col1
  2       , col2s
  3    from ( select col1
  4                , rtrim(col2s,',') col2s
  5                , rn
  6                , sumn
  7             from ( select col1
  8                         , col2
  9                         , sum(n) over (order by col2) sumn
10                      from ( select col1
11                                  , col2
12                                  , case when col1 = lag(col1) over (order by col2) then 0 else 1 end n
13                               from test_grp
14                           ) t
15                  )
16            model
17                  partition by (sumn)
18                  dimension by (row_number() over (partition by sumn order by col2) rn)
19                  measures (col1, cast(col2 as varchar2(100)) col2s)
20                  rules
21                  ( col2s[any] order by rn desc = col2s[cv()] || ',' || col2s[cv()+1]
22                  )
23         )
24   where rn = 1
25   order by sumn
26  /
COL COL2S
aaa 111,222
bbb 333
aaa 444
bbb 555
4 rijen zijn geselecteerd.Regards,
Rob.