Output in one line

Question

Hi all,
I have a table T of the kind:
N
a
a
a
b
b
b
c
c
I want the result as:
a  b    c
3   3   2
For that i have writtena query
select decode(n,'a',count)a,decode(n,'b',count)b,decode(n,'c',count)c
from(select n,count(*)count from t group by n);
But it is giving the output as:
a      b        c
3
         3
                    2 How can i get the output in one line?
Thanks

Answer 1

DimaCit has given a good solution for when you know how many different values you have in advance. If you do not know this, you can code for a number that is higher than you expect or use generated sql to product the desired output. Also I allow for values that are not valid column names.
SQL> host type tmp.sql
set feedback off
set termout off
create table t (N varchar2(4));
insert into t values ('A');
insert into t values ('A');
insert into t values ('A');
insert into t values ('B');
insert into t values ('b');
insert into t values ('b');
insert into t values ('c');
insert into t values ('c');
insert into t values ('c');
insert into t values ('c');
insert into t values ('c');
insert into t values ('6');
insert into t values ('6');
insert into t values ('6');
set pagesize 0
set linesize 32767
set trimspool on
column nl newline
spool tmp.ufi
prompt select
select
  ' count(decode(n,'''||n||
     ''',1, null)) "'||n||
     decode(rv,1,'"','",') nl
from
(select
   n,
   row_number() over (order by n) rn,
   row_number() over (order by n desc) rv,
   sum(1) over() tot from (select distinct n from t)
order by rn
prompt from t;;
spool off
set pagesize 50000
set termout on
@tmp.ufi
drop table t;
SQL> @tmp
         6          A          B          b          c
         3          3          1          2          5
SQL> Edited by: Old DBA on Feb 5, 2009 8:32 PM
Formatting