HOW TO COMBINE MULTIPLE ROWS INTO SINGLE ROWS

Question

Hi,
I have a table with the following data:
CASE-1
TABLE -X
RNO      FROM_SQN     TO_SQN     DATE
==========================================
991      9           11     2010-01-01
991      11           22     2010-01-01
991      22           33     2010-01-01
992      33           44     2010-01-01
I want to see the result data as follows:
RNO      FROM_SQN     TO_SQN     DATE
==========================================
991      9           44     2010-01-01
CASE-2
TABLE -X
RNO      FROM_SQN     TO_SQN     DATE
==========================================
991      9           11     2010-01-01
991      15           22     2010-01-01
991      22           34     2010-01-01
992      33           44     2010-01-01
I want to see the result data as follows:
RNO      FROM_SQN     TO_SQN     DATE
==========================================
991      9           11     2010-01-01
991      15           44     2010-01-01
Please help me how to achieve this using SQL.
Edited by: 986725 on Feb 7, 2013 2:36 AM

Answer 1

with x as
select 991 rno, 9 from_sqn ,11 to_sqn ,to_date('2010-01-01','yyyy-mm-dd') dt
from dual union all
select 991, 15 ,22 ,to_date('2010-01-01','yyyy-mm-dd') from dual union all
select 991, 22 ,33 ,to_date('2010-01-01','yyyy-mm-dd') from dual union all
select 991, 33 ,44 ,to_date('2010-01-01','yyyy-mm-dd') from dual
x_with_group as
select rno,from_sqn,to_sqn,dt,
       sum(sm) over(partition by rno,dt order by from_sqn) sm
from
  select rno,from_sqn,to_sqn,dt,
         from_sqn-
          nvl(lag(to_sqn) over(partition by rno,dt order by from_sqn),0) sm
  from x
select rno,min(from_sqn) from_sqn,max(to_sqn) to_sqn,dt
from x_with_group
group by rno,dt,sm
order by rno,dt,from_sqn;
RNO FROM_SQN TO_SQN DT       
991        9     11 01-jan-2010
991       15     44 01-jan-2010 Edited by: jeneesh on Feb 7, 2013 4:59 PM
Assumed the date values are actually DATE types.
Partition on DT and RNO can be amended as per your requirement..
And assumed your sample data has a typo..
If your data is correct..
with x as
select 991 rno, 9 from_sqn ,11 to_sqn ,to_date('2010-01-01','yyyy-mm-dd') dt
from dual union all
select 991, 15 ,22 ,to_date('2010-01-01','yyyy-mm-dd') from dual union all
select 991, 22 ,33 ,to_date('2010-01-01','yyyy-mm-dd') from dual union all
select 992, 33 ,44 ,to_date('2010-01-01','yyyy-mm-dd') from dual
x_with_group as
select rno,from_sqn,to_sqn,dt,
       sum(sm) over(order by from_sqn) sm
from
  select rno,from_sqn,to_sqn,dt,
         from_sqn-
          nvl(lag(to_sqn) over(order by from_sqn),0) sm
  from x
select min(rno) rno,min(from_sqn) from_sqn,max(to_sqn) to_sqn,min(dt) dt
from x_with_group
group by sm
order by rno,dt,from_sqn;
RNO FROM_SQN TO_SQN DT       
991        9     11 01-jan-2010
991       15     44 01-jan-2010 Edited by: jeneesh on Feb 7, 2013 5:14 PM