Question

MYSQL php RAND()随机查询太慢了，请教改一下这个代码！

SELECT * FROM `table` WHERE (classid=4 or parentid=4) AND delstate='' AND checkinfo=true ORDER BY rand() LIMIT 0,55;

谁能给改一下 让他效率高一些

可以发红bao！

Answer 1

1)随机取出5条记录用sql语句就行了;
mysql如下："select * from youtable order by rand() limit 5";

2)同样随机取5-10条：
$num=rand(5,10);
$sql="select * from youtable order by rand() limit $num";