Mysql select not duplicated values with condition

Question

I'm looking for faster way to run this kind of statment:

SELECT *
FROM `aukcje_przedmioty`
WHERE (
(
    opis NOT
    IN (
        SELECT opis
        FROM aukcje_przedmioty
        WHERE ( aktywne =1 AND user_id =6 )
    )
)
AND aktywne =0
AND user_id =6
)

table aukcje_przedmioty

Answer 1

you can try something like

SELECT a.*
FROM `aukcje_przedmioty` a 
JOIN 
(
  SELECT opis,user_id
  FROM aukcje_przedmioty
  GROUP BY opis,user_id
  HAVING max(aktywne) = 0
) x 
ON 
x.user_id = a.user_id and 
x.opis = a.opis
WHERE user_id = 6

http://sqlfiddle.com/#!2/16774/6

Use explain on your setup to see what would work best for you.