SQL Query to get the desired result

Question

Can someone give the SQL to get this output.
input is like this in table.
cola     colb     fromdate     todate
1     100     1/5/2010     1/9/2010
1     101     1/10/2010     1/25/2010
1     102     1/26/2010     12/31/2900
2     201     3/1/2011     3/10/2011
2     202     3/11/2011     12/31/2900
3     301     1/5/2010     1/9/2010
3     302     1/10/2010     1/25/2010
3     303     1/26/2010     1/28/2010
3     304     1/29/2010     12/31/2900
I want to get the output like this.
cola     colb     fromdate     todate
1     100     1/5/2010     1/9/2010
2     201     3/1/2011     3/10/2011
3     301     1/5/2010     1/9/2010
More info:
I want to get the rows where fromdate is the min(fromdate) from each cola's unique values i.e. 1,2,3
Please let me know the SQL.
Thanks.
[email protected]

Answer 1

This way!!!
with data(cola, colb, st_dt, ed_dt) as
select 1,     100,     to_date('01/05/2010', 'MM/DD/YYYY'),     to_date('01/09/2010', 'MM/DD/YYYY') from dual union all
select 1,     101,  to_date('01/10/2010', 'MM/DD/YYYY'),     to_date('01/25/2010', 'MM/DD/YYYY') from dual union all
select 1,     102,     to_date('01/26/2010', 'MM/DD/YYYY'),     to_date('12/31/2900', 'MM/DD/YYYY') from dual union all
select 2,     201,     to_date('03/01/2011', 'MM/DD/YYYY'),     to_date('03/10/2011', 'MM/DD/YYYY') from dual union all
select 2,     202,     to_date('03/11/2011', 'MM/DD/YYYY'),     to_date('12/31/2900', 'MM/DD/YYYY') from dual union all
select 3,     301,     to_date('01/05/2010', 'MM/DD/YYYY'),     to_date('01/09/2010', 'MM/DD/YYYY') from dual union all
select 3,     302,     to_date('01/10/2010', 'MM/DD/YYYY'),     to_date('01/25/2010', 'MM/DD/YYYY') from dual union all
select 3,     303,     to_date('01/26/2010', 'MM/DD/YYYY'),     to_date('01/28/2010', 'MM/DD/YYYY') from dual union all
select 3,     304,     to_date('01/29/2010', 'MM/DD/YYYY'),     to_date('12/31/2900', 'MM/DD/YYYY') from dual
select cola, colb, st_dt, ed_dt
  from (
        select cola, colb, st_dt, ed_dt,
               row_number() over (partition by cola order by st_dt) rn
          from data
       ) a
where a.rn = 1;
COLA COLB ST_DT     ED_DT  
   1  100 05-JAN-10 09-JAN-10
   2  201 01-MAR-11 10-MAR-11
   3  301 05-JAN-10 09-JAN-10