id_feature|id_product|id_feature_value
Z tabeli chcę pobrać id_product dla których id_feature_value = 5 i id_feature_value = 14 i id_feature_value=17
i szczerze jakoś zgłupiałem

SELECT id_product FROM tabela WHERE id_feature_value=5 AND id_feature_value=14 AND id_feature_value=17
WHERE id_feature_value IN (5, 14, 17) GROUP BY id_product