如果你关心性能，你也应该尝试关联子查询:

If you care about performance, you should also try a correlated subquery:

SELECT id, workout_id, level_id, a.user_id, total_time, score, datetime_added
FROM nodefit_rankings_fitness nrf
WHERE nrf.id = (SELECT TOP (1) nrf2.id
                FROM nodefit_rankings_fitness nrf2
                WHERE nrf2.user_id = nrf.user_id
                ORDER BY nrf2.score DESC
               )
ORDER BY score DESC, datetime_added DESC;

特别是，这可以利用 nodefit_rankings_fitness(user_id, score desc, id) 上的索引.

In particular, this can take advantage of an index on nodefit_rankings_fitness(user_id, score desc, id).