SELECT A 
FROM S t1 WHERE
B = (SELECT COUNT(1) AS "B相同的数量" FROM S where B=t1.B)

------解决方案--------------------
列举 表结构和数据以及想要的结果  不然谁知道LZ说的什么意思啊

------解决方案--------------------

这个意思？
SQL code

create table t1 (t_id number(10),a varchar2(10),b varchar2(10),c varchar2(10));

insert into t1 values (1,'1','2','3');
insert into t1 values (2,'4','5','6');
insert into t1 values (3,'1','2','3');
insert into t1 values (4,'1','3','3');
insert into t1 values (5,'2','2','3');
insert into t1 values (6,'1','2','3');
insert into t1 values (7,'1','3','3');

select a,b,c,max(d) 重复数量 from
(select a,b,c,rank() over(partition by a,b,c order by t_id) d
from t1)
group by a,b,c


a   b   c   重复数量
---------------------------------------
1    2    3    3
1    3    3    2
2    2    3    1
4    5    6    1

------解决方案--------------------
只是要一个总计的话，不用这么麻烦。

SQL code
select count(*) from table 
  where rowid not in (
         select max(rowid) from table
         group by a,b,c)