Oracle query where one column with multiple values must be different - oracle

Question

I'm having trouble trying to come up with a query that retrieves COLUMN_A where:
COLUMN_C is having count > 1
And COLUMN_B's values are different.
Table contents
COLUMN_A COLUMN_B COLUMN_C
-------------------------------- ---------------- ---------
000111222 AAAAAAAAA 100
000111222 BBBBBBBBB 100
000111222 CCCCCCCCC 300
000111222 CCCCCCCCC 300
000888999 DDDDDDDDD 300
000888999 DDDDDDDDD 300
777666555 EEEEEEEEE 100
777666555 FFFFFFFFF 100
234567890 GGGGGGGGG 100
234567890 GGGGGGGGG 100
444333111 HHHHHHHHH 100
Expected result
COLUMN_A COLUMN_B COLUMN_C
-------------------------------- ---------------- ---------
000111222 AAAAAAAAA 100
000111222 BBBBBBBBB 100
777666555 EEEEEEEEE 100
777666555 FFFFFFFFF 100
This is where I'm stuck at:
select COLUMN_A, count(*) from SOME_TABLE where COLUMN_C = '100' group by COLUMN having count(*) > '1';
But this query retrieves:
COLUMN_A COLUMN_B COLUMN_C
-------------------------------- ---------------- ---------
000111222 AAAAAAAAA 100
000111222 BBBBBBBBB 100
777666555 EEEEEEEEE 100
777666555 FFFFFFFFF 100
234567890 GGGGGGGGG 100
234567890 GGGGGGGGG 100
I strongly suspect the query lacks a distinct or a count somewhere but, for the life of me, nothing comes to mind.
Any info would be greatly appreciated.

Answer 1

We can try to use two count window functions in the subquery for your grouping logic.
SELECT t1.COLUMN_A ,t1.COLUMN_B ,t1.COLUMN_C
FROM (
select t1.*,
count(*) OVER(PARTITION BY COLUMN_A,COLUMN_B) cnt1,
COUNT(*) OVER(PARTITION BY COLUMN_A,COLUMN_C) cnt2
from SOME_TABLE t1
) t1
WHERE cnt1 = 1 AND cnt2 > 1
sqlfiddle

Answer 2

You can use:
SELECT column_a, column_b, column_c
FROM (
SELECT t.*,
COUNT(column_b) OVER (PARTITION BY column_a, column_c) AS cnt_all,
COUNT(DISTINCT column_b) OVER (PARTITION BY column_a, column_c)
AS cnt_dst
FROM table_name t
)
WHERE cnt_all = cnt_dst
AND cnt_dst > 1
Which, for the sample data:
CREATE TABLE table_name (COLUMN_A, COLUMN_B, COLUMN_C) AS
SELECT '000111222', 'AAAAAAAAA', 100 FROM DUAL UNION ALL
SELECT '000111222', 'BBBBBBBBB', 100 FROM DUAL UNION ALL
SELECT '000111222', 'CCCCCCCCC', 300 FROM DUAL UNION ALL
SELECT '000111222', 'CCCCCCCCC', 300 FROM DUAL UNION ALL
SELECT '000888999', 'DDDDDDDDD', 300 FROM DUAL UNION ALL
SELECT '000888999', 'DDDDDDDDD', 300 FROM DUAL UNION ALL
SELECT '777666555', 'EEEEEEEEE', 100 FROM DUAL UNION ALL
SELECT '777666555', 'FFFFFFFFF', 100 FROM DUAL UNION ALL
SELECT '234567890', 'GGGGGGGGG', 100 FROM DUAL UNION ALL
SELECT '234567890', 'GGGGGGGGG', 100 FROM DUAL UNION ALL
SELECT '444333111', 'HHHHHHHHH', 100 FROM DUAL;
Outputs:
COLUMN_A
COLUMN_B
COLUMN_C
000111222
AAAAAAAAA
100
000111222
BBBBBBBBB
100
777666555
EEEEEEEEE
100
777666555
FFFFFFFFF
100
db<>fiddle here