组中所有分组的SQL

Question

假设我有表foo

A     B     C
==============
1     1     1
1     2     3
1     2     4
1     3     6
2     2     6

我想要所有具有重复AB的C集。 就像是：

select all(C) from foo group by a, b having count(b) > 1

我希望结果是

all(C)
===
 3
 4

在Oracle SQL中有没有简单的方法可以做到这一点？

Answer 1

SELECT t1.c
  FROM foo t1
       JOIN foo t2 ON (t1.a = t2.a AND 
                       t1.b = t2.b AND 
                       t1.rowid != t2.rowid)

应该给你你想要的。 使用解析函数可能会更有效率

SELECT c
  FROM (SELECT f.*,
               count(*) over (partition by a, b) cnt
          FROM foo f)
 WHERE cnt > 1

Answer 2

尝试这个：

SELECT C
FROM
(select C, COUNT(*) OVER(PARTITION BY A, B) AS DUPLICATES
from MY_TABLE) AS RESULTS
WHERE DUPLICATES > 1

Answer 3

我想到了。 我用了

select f.c from foo f
join (select a, b from foo group by a, b having count(c) > 1) dupes
on dupes.a = f.a and dupes.b = f.b;