Divide by couples of elements in a table - sql

Question

I have this table:
ELEMENTO VALOR
-------------------------
ELEMENT1_SUFFIX1 2
ELEMENT1_SUFFIX2 4
ELEMENT2_SUFFIX1 5
ELEMENT2_SUFFIX2 15
I would like to generate new entries by dividing each couple of elements and suffixes. For each partition of element, I would like to divide suffix2/suffix1 and generate an entry with element_result. Like the below.
ELEMENTO VALOR
-------------------------
ELEMENT1_SUFFIX1 2
ELEMENT1_SUFFIX2 4
ELEMENT2_SUFFIX1 5
ELEMENT2_SUFFIX2 15
ELEMENT1_RESULT 2
ELEMENT1_RESULT 3
The table can be generated with the below code.
with aux (elemento, valor) as
( select 'ELEMENT1_SUFFIX1', 2 from dual
UNION ALL
select 'ELEMENT1_SUFFIX2', 4 from dual
UNION ALL
select 'ELEMENT2_SUFFIX1', 5 from dual
UNION ALL
select 'ELEMENT2_SUFFIX2', 10 from dual
)
select aux.* from aux;
This is what I've tried so far, but I am pretty sure there must be a better solution.
with aux (elemento, valor) as
( select 'ELEMENT1_SUFFIX1', 2 from dual
UNION ALL
select 'ELEMENT1_SUFFIX2', 4 from dual
UNION ALL
select 'ELEMENT2_SUFFIX1', 5 from dual
UNION ALL
select 'ELEMENT2_SUFFIX2', 15 from dual
),
aux2 as
(select aux.*,
valor/max(
case
when regexp_substr(elemento, '[^_]+', 1, 2) = 'SUFFIX1'
then valor
end) over (partition by REGEXP_SUBSTR(elemento,'[^_]+',1,1)) new_value
from aux
)
select * from aux
union all
select REGEXP_SUBSTR(elemento,'[^_]+',1,1)
|| '_RESULT',
new_value valor
from aux2
where regexp_substr(elemento, '[^_]+', 1, 2) = 'SUFFIX2';

Answer 1

Yet another variation.
Sample data:
SQL> WITH
2 aux (elemento, valor)
3 AS
4 (SELECT 'ELEMENT1_SUFFIX1', 2 FROM DUAL
5 UNION ALL
6 SELECT 'ELEMENT1_SUFFIX2', 4 FROM DUAL
7 UNION ALL
8 SELECT 'ELEMENT2_SUFFIX1', 5 FROM DUAL
9 UNION ALL
10 SELECT 'ELEMENT2_SUFFIX2', 15 FROM DUAL
11 )
Query:
12 -- existing rows
13 select elemento, valor
14 from aux
15 union all
16 -- calculated rows
17 select
18 substr(elemento, 1, instr(elemento, '_') - 1) ||'_RESULT' as elemento,
19 max(case when substr(elemento, -1) = 2 then valor end) /
20 max(case when substr(elemento, -1) = 1 then valor end) as valor
21 from aux
22 group by substr(elemento, 1, instr(elemento, '_') - 1);
ELEMENTO VALOR
----------------------- ----------
ELEMENT1_SUFFIX1 2
ELEMENT1_SUFFIX2 4
ELEMENT2_SUFFIX1 5
ELEMENT2_SUFFIX2 15
ELEMENT1_RESULT 2
ELEMENT2_RESULT 3
6 rows selected.
SQL>

Answer 2

We can use an aggregation/pivot approach along with a union here:
WITH cte AS (
SELECT SUBSTR(ELEMENTO, 1, INSTR(ELEMENTO, '_') - 1) || '_RESULT' AS ELEMENTO,
MAX(CASE WHEN SUBSTR(ELEMENTO, INSTR(ELEMENTO, '_') + 1) = 'SUFFIX2'
THEN VALOR END) /
MAX(CASE WHEN SUBSTR(ELEMENTO, INSTR(ELEMENTO, '_') + 1) = 'SUFFIX1'
THEN VALOR END) AS VALOR
FROM yourTable
GROUP BY SUBSTR(ELEMENTO, 1, INSTR(ELEMENTO, '_') - 1)
)
SELECT ELEMENTO, VALOR
FROM
(
SELECT ELEMENTO, VALOR, 1 AS pos FROM yourTable
UNION ALL
SELECT ELEMENTO, VALOR, 2 FROM cte
) t
ORDER BY pos, ELEMENTO;

Answer 3

Try this:
with aux (elemento, valor) as
( select 'ELEMENT1_SUFFIX1', 2 from dual
UNION ALL
select 'ELEMENT1_SUFFIX2', 4 from dual
UNION ALL
select 'ELEMENT2_SUFFIX1', 5 from dual
UNION ALL
select 'ELEMENT2_SUFFIX2', 15 from dual
), rawdata (elemento, valor, group_id, row_id) AS
(
select aux.*
,DENSE_RANK() OVER (ORDER BY SUBSTR(elemento, 1, INSTR(elemento, '_')-1))
,ROW_NUMBER() OVER (PARTITION BY SUBSTR(elemento, 1, INSTR(elemento, '_')-1) ORDER BY SUBSTR(elemento, INSTR(elemento, '_')+1))
from aux
)
SELECT *
FROM aux
UNION ALL
SELECT CONCAT(CONCAT('ELEMENT', A.group_id),'_RESULT')
,B.valor / a.valor
FROM rawdata A
INNER JOIN rawdata B
ON A.group_id = b.group_id
AND A.row_id = b.row_id -1