SQL选择所最近一条记录
SELECT t1.*
FROM tbl AS t1 INNER JOIN
(SELECT tbl.userId, MAX(date) AS lastDate FROM tbl
GROUP BY tbl.userId) AS t2 ON
t1.userId = t2.userId
AND t1.date = t2.lastDate
FROM tbl AS t1 INNER JOIN
(SELECT tbl.userId, MAX(date) AS lastDate FROM tbl
GROUP BY tbl.userId) AS t2 ON
t1.userId = t2.userId
AND t1.date = t2.lastDate