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php随机取mysql记录方法示例

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Release: 2016-05-25 16:37:55
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在php中要随机取mysql记录我们可以直接使用mysql_query来执行mysql中的select rand函数获取的数据并读出来,下面我来给大家介绍一下具体实例.

方法一,代码如下:

select * from tablename order by rand() limit 1
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把 limit 后面的数值改为你想随机抽取的条数,这里只取一条.

方法二,代码如下:

$query= "SELECT count(*) as count FROM recommends"; 
.... 
$max_num = $row['count']; // 取记录总数 
srand((double)microtime()*1000000); // 随机数种子 
$se_pos = rand(0, $max_num); // 随机数范围 
$length = 6; // 记录条数 
if (($max_num - $se_pos) <= $length) { 
$se_pos = $max_num - $se_pos; // 记录数不足6条的情况 
}
$query = "SELECT * FROM recommendsn limit ".$se_pos.",".$length;
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例3,假设有一个名为xyj的数据库,库中有表obj,表中有一字段为name,现在要实现从表里随机选取一条记录,具体程序如下:

<?php
$db = mysql_connect("localhost", "root");
mysql_select_db("xyj", $db);
$result = mysql_query("SELECT * FROM obj", $db);
$max_num = mysql_num_rows($result); //取得数据库的记录数
srand((double)microtime() * 10000000); //生成随机数种子。
$se_pos = rand(0, $max_num - 1); //从0到最大记录数取随机数
$length = 30; //设定共取多少条记录
//下面是取出指定数目的记录。
$result_lim = mysql_query("select * from obj limit $se_pos,$length", $db);
$myrow_lim = mysql_fetch_array($result_lim);
printf("%sn", $se_pos); //显示随机得到的记录号
printf("%sn", $myrow_lim["name"]); //显示随机得到的记录的name字段
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转载随意~请带上教程地址吧^^

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