Gebruik LEFT JOIN/IS NULL
SELECT DISTINCT
i.data
FROM IMAGE i
JOIN USER_IMAGE ui ON ui.image_id = i.id
LEFT JOIN USER u ON u.id = ui.user_id
AND u.user = ?
WHERE u.id IS NULL
Gebruik NOT IN
SELECT DISTINCT
i.data
FROM IMAGE i
JOIN USER_IMAGE ui ON ui.image_id = i.id
WHERE ui.user_id NOT IN (SELECT u.id
FROM USER u
WHERE u.user = ?)
Gebruik NOT EXISTS
SELECT DISTINCT
i.data
FROM IMAGE i
JOIN USER_IMAGE ui ON ui.image_id = i.id
WHERE NOT EXISTS(SELECT NULL
FROM USER u
WHERE u.id = ui.user_id
AND u.user = ?)
Prestaties:
De LEFT JOIN/IS NULL
en NOT IN
gelijkwaardige prestaties leveren - de NOT EXISTS
is ~30% minder efficiënt. Zie dit voor meer details
.