在MySQL中从相同(随机)记录中选择2列的最快方法是什么? [英] What is the fastest way of selecting 2 columns from the same (random) record in MySQL?

问题描述

我希望我从同一条记录中随机检索一对列.我听说兰德的效率很低，所以我想用另一种方式. (很多文章都这样认为，包括 http://akinas.com/pages/en/blog/mysql_random_row/).

I want I retrieve a pair of columns from the same record, in a random basis. I've heard that Rand is very inefficient, however, so I'd like to use a different way. (Lots of articles claims so, including http://akinas.com/pages/en/blog/mysql_random_row/).

是的，我的标题几乎说明了一切. 例子: 记录:
12，詹姆斯，单簧管，鸡肉
16，比利，鼓，培根
15，Shane，吉他，比萨饼

So yeah, my title pretty much says it all. Example: Records:
12, James, Clarinet, Chicken
16, Billy, Drums, Bacon
15, Shane, Guitar, Pizza

系统将随机选择一条记录.然后 回声一个名叫$ firstname的男孩喜欢$ favoritefood".

The system would randomly pick a record. It'll then echo 'A boy named $firstname likes $favoritefood'.

类似的东西.帮助吗?

推荐答案

有关SQL注入的标准免责声明.这应该可以，但是我没有尝试:

Standard disclaimer about SQL injection. This should work, but I didn't try it:

// Get the number of rows in the table
$count = mysql_fetch_assoc(mysql_query('SELECT COUNT(`id`) AS `count` FROM `table`'));
// Use those to generate a random number
$rand = rand(1,$count['count']);
// Select the two columns we need, and use limit to set the boundaries
$query = 'SELECT `firstName`, `favoriteFood` FROM `table` LIMIT '.$rand.',1';
// Run the query
if(($result = mysql_query($query)) !== FALSE) {
    // Dump the result into two variables
    list($firstname, $favoritefood) = mysql_fetch_assoc($result);
    // Echo out the result
    echo 'A boy named '.$firstname.' likes '.$favoritefood;
}

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