Zkuste:
SELECT a.name,a.email, GROUP_CONCAT(c.code)
FROM users a
JOIN code_to_user_ref b ON a.user_id = b.user_id
JOIN codes c ON b.code_id = c.code_id
GROUP BY a.name,a.email
Výsledek by byl:
| NAME | EMAIL | CODE/S OWNED |
|------|--------------|---------------|
| jane | jane@doe.com | Vb#4%6 |
| joe | joe@doe.com | Cv@3$5,xC1@3$ |
| john | john@doe.com | Bn%6&8 |
Zde je SQLFiddle .