How to use 'HAVING' without 'GROUP BY', what's wrong in this query?

Question

Hi!

'Having' can be used without 'Group by' as well, table has the data but this query is not returning any answers is there anything wrong with this query?

SELECT SUM(ACCOUNT_TYPE)
FROM TBLCUSTCHANNEL
HAVING SUM(ACCOUNT_TYPE) <=10

Please do guide in Oracle and in SQL.

Thanks in advance