大家好，对mysql 高效率随机获取n条数据感兴趣的小伙伴，下面一起跟随三零脚本的小编来看看mysql 高效率随机获取n条数据的例子吧。

ID连续的情况下（注意不能带where，否则结果不好）：

---- 来自www.q3060.com 
SELECT *
FROM `mm_account` AS t1 JOIN (SELECT ROUND(RAND() * (SELECT MAX(id) FROM `mm_account`)) AS id) AS t2
WHERE t1.id >= t2.id
ORDER BY t1.id ASC LIMIT 4;

ID不连续的情况下：

---- 来自www.q3060.com 
SELECT * FROM `mm_account` 
WHERE id >= (SELECT floor(RAND() * (SELECT MAX(id) FROM `mm_account`)))  and city="city_91" and showSex=1
ORDER BY id LIMIT 4;

假设你的表叫做mm_account，并且有一个字段叫id。最快的方法如下（随机获取5条）：

---- 来自www.q3060.com 
SELECT * FROM mm_account WHERE id >= ((SELECT MAX(id) FROM mm_account)-(SELECT MIN(id) FROM mm_account)) * RAND() + (SELECT MIN(id) FROM mm_account) limit 5;

如果带where语句，上面就不适合了。带where语句请看下面：

---- 来自www.q3060.com 
SELECT *
FROM `mm_account` AS t1 JOIN (SELECT ROUND(RAND() * (
(SELECT MAX(id) FROM `mm_account` where id<1000 )-(SELECT MIN(id) FROM `mm_account` where id<1000 ))+(SELECT MIN(id) FROM `mm_account` where id<1000 )) AS id) AS t2
WHERE t1.id >= t2.id
ORDER BY t1.id LIMIT 5;