mysql随机获取表数据

SELECT t1.* 
FROM geo_road_status t1
JOIN(SELECT ROUND(RAND() * ((SELECT MAX(id) FROM geo_road_status) - (SELECT MIN(id) FROM geo_road_status)) + (SELECT MIN(id) FROM geo_road_status)) id) t2
WHERE 1=1
	AND t1.id >= t2.id
ORDER BY t1.id 
LIMIT 100

从社区扒拉下来的方法，关键计算在于关联当前表中随机自增id，select round(rand() * (max(aa) - min(aa)) + min(aa))

表数据量大的情况下，性能比order by rand()