How to group using SQL for the required output.

Question

hi all,
i'm currently using oracle 10.2.0.4.0
create table script :
CREATE TABLE FORTEST
( gpno VARCHAR2(10 BYTE),
  classnumber  VARCHAR2(10 byte),
  age_min NUMBER,
  age_max NUMBER,
  amount NUMBER)insert statement:
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 01,0,29,1)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 01,30,35,2)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 01,36,40,3)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 02,0,29,1)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 02,30,35,2)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 02,36,40,5)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 03,0,29,1)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 03,30,35,2)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G123' , 03,36,40,3)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G124' , 01,0,29,1)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G124' , 01,30,35,2)
insert into fortest  (GPNO,classnumber,age_min,age_max,amount) values
('G124' , 01,36,40,3) output required:
gpno    classnumber    age_min    age_max    amount
G123    1,3                0        29        1
G123    1,3                30       35        2
G123    1,3                36       40        3
G123    2                  0        29        1
G123    2                  30       35        2
G123    2                  36       40        5
G124    1                  0        29        1
G124    1                  30       35        2
G124    1                  36       40        3since for gpno g123, classnumber 1 and 3, the rates are same across all age_min and age_max they need to be grouped together.
even though gpno 123 classnumber 2 has same rates as classesnumber 1 and 3 for age bands 0 to 29 and 30 to 35,
the rates are different for age bands 36 to 40. so it should not be grouped together. how can i do this in SQL
any help is appreciated.
thanks in advance.

Answer 1

Hi,
Tricky problem!
Unfortunately, LISTAGG was only introduced in Oracle 11.2. About half of the complexity here is the string aggregation, that is, forming the list of classnumbers, such as '1,3', using only functions available in Oracle 10.2.
Here's one solution:
WITH     got_gpno_classnumber_cnt   AS
     SELECT     gpno, classnumber, age_min, age_max, amount
     ,     COUNT (*) OVER ( PARTITION BY  gpno
                                  ,            classnumber
                      )   AS gpno_classnumber_cnt
     FROM    fortest
--     WHERE     ...     -- If you need any filtering, this is where it goes
,     pairs          AS
     SELECT    a.gpno
     ,       a.classnumber
     ,       MIN (b.classnumber)
                OVER ( PARTITION BY  a.gpno
                          ,                    a.classnumber
                  )     AS super_classnumber
     FROM       got_gpno_classnumber_cnt  a
     JOIN       got_gpno_classnumber_cnt  b  ON   a.gpno     = b.gpno
                                  AND  a.age_min     = b.age_min
                                AND  a.age_max     = b.age_max
                                AND  a.amount     = b.amount
                                AND  a.gpno_classnumber_cnt
                                        = b.gpno_classnumber_cnt
     GROUP BY  a.gpno
     ,            a.classnumber
     ,       b.classnumber
     HAVING       COUNT (*)     = MIN (a.gpno_classnumber_cnt)
,     got_rnk          AS
     SELECT DISTINCT     
             gpno, classnumber, super_classnumber
     ,     DENSE_RANK () OVER ( PARTITION BY  gpno
                               ,                    super_classnumber
                               ORDER BY          classnumber
                       )         AS rnk
     FROM    pairs
,     got_classnumbers     AS
     SELECT     gpno, classnumber, super_classnumber
     ,      SUBSTR ( SYS_CONNECT_BY_PATH (classnumber, ',')
                   , 2
                 )     AS classnumbers     
     FROM     got_rnk
     WHERE     CONNECT_BY_ISLEAF = 1
     START WITH     rnk             = 1
     CONNECT BY     rnk             = PRIOR rnk + 1
          AND     gpno             = PRIOR gpno
          AND     super_classnumber  = PRIOR super_classnumber
SELECT DISTINCT
       g.gpno
,       c.classnumbers
,       g.age_min
,       g.age_max
,       g.amount
FROM       got_gpno_classnumber_cnt  g
JOIN       got_classnumbers         c  ON   c.gpno        = g.gpno
                             AND  c.classnumber  = g.classnumber
ORDER BY  g.gpno
,            c.classnumbers
;Output (just as you requested):
GPNO       CLASSNUMBERS       AGE_MIN    AGE_MAX     AMOUNT
G123       1,3                      0         29          1
G123       1,3                     30         35          2
G123       1,3                     36         40          3
G123       2                        0         29          1
G123       2                       30         35          2
G123       2                       36         40          5
G124       1                        0         29          1
G124       1                       30         35          2
G124       1                       36         40          3