ORA-00907: missing right parenthesis on query with subqueries and EXCEPT operator I am getting


  ORA-00907: missing right parenthesis 


for the following query:

SELECT PEOPLE.NAME FROM
CLIENTS K INNER JOIN PEOPLE ON K.ID_L = PEOPLE.ID_L
WHERE NOT EXISTS
(
(SELECT DISTINCT ARTIST.ID_U
FROM CLIENTS INNER JOIN ADORES ON CLIENTS.ID_L = ADORES.ID_L
INNER JOIN ARTIST ON ADORES.ID_U = ARTIST.ID_U
WHERE CLIENTS.ID_L = K.ID_L)

EXCEPT

(SELECT DISTINCT ARTIST.ID_U
FROM CLIENTS INNER JOIN BOUGHT ON CLIENTS.ID_L = BOUGHT.ID_L
INNER JOIN ARTWORK ON BOUGHT.ID_D = ARTWORK.ID_D
INNER JOIN ARTIST ON ARTWORK.ID_U = ARTIST.ID_U
WHERE CLIENTS.ID_L = K.ID_L)
)


I've checked both subqueries - both are ok. It works if I remove the EXCEPT operator and only use one subquery (but I need to actually test that both are equal).

Any idea on what the problem is?
EXCEPT is an SQL standard that is not available in Oracle. You probably want to use the Oracle equivalent of MINUS.
See here for a good answer on the two keywords.
Edit: @a_horse_with_no_name corrected thanks!