使用:
SELECT m.id,
m.brand,
x.detid,
x.parentid,
x.model
FROM T_MASTER m
JOIN T_DETAIL x ON x.parentid = m.id
JOIN (SELECT d.parentid,
MAX(d.detid) AS max_detid
FROM T_DETAIL d
GROUP BY d.parentid) y ON y.max_detid = x.detid
AND y.parentid = x.parentid