Mysql随机访问记录

之前有朋友问过我这个问题，不过我当时的想法是很拙劣的，很费劲的！

到网上找了下才知道Mysql有这个功能：

SELECT * FROM `one7_category` ORDER BY RAND() LIMIT 5;

不过，又在群里问了下朋友，说这个效率不高，又google了下，终于在老蒋记事本找到了该文章 mysql使用rand随机查询记录效率测试

SELECT * FROM `table`
WHERE id >= (SELECT floor( RAND() * ((SELECT MAX(id) FROM `table`)-(SELECT MIN(id) FROM `table`)) + (SELECT MIN(id) FROM `table`))) 
ORDER BY id LIMIT 1;

SELECT *
FROM `table` AS t1 JOIN (SELECT ROUND(RAND() * ((SELECT MAX(id) FROM `table`)-(SELECT MIN(id) FROM `table`))+(SELECT MIN(id) FROM `table`)) AS id) AS t2
WHERE t1.id >= t2.id
ORDER BY t1.id LIMIT 1;