[英]How to select RAND() between 1-n
I'd like to use RAND()
in a query to be able to do the following: 我想在查询中使用RAND()
来执行以下操作:
ODER BY id DESC
and allow RAND()
to choose between last 3 inserted rows in the table. ODER BY id DESC
并允许RAND()
在表中最后插入的3行之间进行选择。 On the front-end when page is refreshed function rand will choose between 5 - 8 (on the table example) and show any data between those numbers. 在刷新页面的前端,功能rand将在5-8之间选择(在表格示例中),并显示这些数字之间的任何数据。
function rand()
{
$sth = $this->db->prepare("SELECT rows FROM table ORDER BY id LIMIT 1");
$sth->execute();
}
+--------------+
| id | name |
+--------------+
| 1 | Jon |
| 2 | Sarah |
| 3 | Stevie |
| 4 | Stew |
| 5 | Dave |
| 6 | Kar |
| 7 | Stevo |
| 8 | Blake |
+----+---------+
+----+ | + ---- + | id | id | +----+ | + ---- + | | | | | | | | | | | | | | | | | | | | | | | | | | | | | || || | |
If I understand your question correctly, I think you need this: 如果我正确理解了您的问题,我认为您需要这样做:
SELECT id, name
FROM
(SELECT id, name FROM table ORDER BY id DESC LIMIT 3) s
ORDER BY rand()
LIMIT 1
Have you tried this: 您是否尝试过:
SELECT name
FROM users
ORDER BY RAND()
LIMIT 3
http://davidwalsh.name/mysql-random http://davidwalsh.name/mysql-random
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