Unnamed

SELECT klant, naam, voorlFROM (    SELECT klant, COUNT(srtc) AS aantal    FROM verkoop       JOIN artikel ON verkoop.art = artikel.art    WHERE srtc IN (        SELECT DISTINCT srtc         FROM artikel            JOIN inkart ON inkart.art = artikel.art         WHERE lev = 1) AS soorten      AND COUNT(srtc) IN (                SELECT COUNT(DISTINCT srtc) AS temp                FROM artikel                    JOIN inkart ON inkart.art = artikel.art                WHERE lev = 1                ) AS aantalsrt    GROUP BY klant     ) AS klanten;