SQL oracle : Group and Count data - sql

Question

I have a table like this:
+-----+------+
| acc | CASE |
+-----+------+
| 001 | a |
| 001 | b |
| 001 | c |
| 002 | a |
| 002 | b |
| 003 | b |
| 003 | c |
| 004 | a |
| 005 | b |
| 006 | b |
| 007 | a |
| 007 | b |
| 007 | c |
| 008 | a |
| 008 | b |
| n | x |
+-----+------+
I have no idea how to group and count data with
+-----------+-----------+
| case | count_acc |
+-----------+-----------+
| a | 1 |
| b | 2 |
| c | 0 |
| a+b | 2 |
| b+c | 1 |
| a+b+c | 2 |
| a+b+c+…+x | n |
+-----------+-----------+
in case a+b,b+c ... a+b+c+…+x I can't group case and count acc. Do you have any idea to group and count?

Answer 1

select b.case,count(distinct(a.acc)) as account from
test a , (select acc , rtrim(case,'+') case
from ( select acc , case , rn from test
model
partition by (acc)
dimension by (row_number() over (partition by acc order by case) rn )
measures (cast(case as varchar2(10)) case)
rules
(case[any] order by rn desc = case[cv()]||'+'||case[cv()+1])
)
where rn = 1) b
where a.acc = b.acc
group by b.case

Answer 2

You can achieve the same using LISTAGG in oracle
with test as ( select 001 acc , 'a' case FROM DUAL UNION
SELECT 001 , 'b' FROM DUAL UNION
SELECT 001 , 'c' FROM DUAL UNION
SELECT 002 , 'a' FROM DUAL UNION
SELECT 002 , 'b' FROM DUAL UNION
SELECT 003 , 'b' FROM DUAL UNION
SELECT 003 , 'c' FROM DUAL UNION
SELECT 004 , 'a' FROM DUAL UNION
SELECT 005 , 'b' FROM DUAL UNION
SELECT 006 , 'b' FROM DUAL UNION
SELECT 007 , 'a' FROM DUAL UNION
SELECT 007 , 'b' FROM DUAL UNION
SELECT 007 , 'c' FROM DUAL UNION
SELECT 008 , 'a' FROM DUAL UNION
SELECT 008 , 'b' FROM DUAL )
select case,count(1) from
(
SELECT count(1),acc, LISTAGG(case, '+') WITHIN GROUP (ORDER BY acc) AS case
FROM test
GROUP BY acc) GROUP BY case order by 1;
SQL fiddle here

Answer 3

First you have to organize your data, grouping the ACC and Aggregating the CASE
SELECT
LISTAGG (case,'+') WITHIN GROUP (ORDER BY case) case,
ACC
FROM TEST
GROUP BY ACC
Them you will be able to count:
SELECT case, count(*) FROM (
SELECT
LISTAGG (case,'+') WITHIN GROUP (ORDER BY case) case,
ACC
FROM TEST
GROUP BY ACC
) GROUP BY case
ORDER BY CASE;
In case you don't have function LISTAGG, below 11g for example, refer to this website:
http://oracle-base.com/articles/misc/string-aggregation-techniques