Do I need a sub-query and getting ORA-00937 error

Question

I'm writing a query where I want returned all data that is in a list 510 and all duplicate entries for the AID are eliminated.
select *
from entities e
where e.list_id in
(select aid
from entities e
where e.list_id = 510
having count(e.aid) > 1);
When I run this, I get ORA-00937: not a single-group group function.
I google the error and see
http://ora-00937.ora-code.com/
Which tells me I can't have a group function and individual column expression.
So I removed the group by, but I still get the errors, and for some reason when I put the alias e for the aid in the subquery, I still get the same error.
Hopefully this makes sense what I'm asking...
thanks

Answer 1

if you want to select rows that eliminate duplicates then you should be using distinct. And if you want to get the duplicate rows then,
select *
from entities e1
where e1.rowid <
(select max(e2.rowid)
from entities e2
where e2.list_id = 510
and e1.aid = e2.aid);