使用PDO的mysql_num_rows的替代方法 [英] Alternative for mysql_num_rows using PDO

问题描述

现在我有一个PHP文件，该文件执行MYSQL查询，然后对像这样的行进行计数:

Right now I have a PHP file that does a MYSQL query and then counts rows like this:

$count=mysql_num_rows($result);


if ($count == 1) {
    $message = array('status' => 'ok');
} else {
    $message = array('status' => 'error');
}

这正常工作，但是我试图将所有PHP文件更改为使用PDO.那么如何使用PDO做到这一点呢?

This works fine but I'm trying to change all my PHP files to use PDO. So how can this be done with PDO?

推荐答案

$res = $DB->query('SELECT COUNT(*) FROM table');
$num_rows = $res->fetchColumn();

或

$res = $DB->prepare('SELECT COUNT(*) FROM table');
$res->execute();
$num_rows = $res->fetchColumn();

您也可以使用它来询问数据是否存在或被选择:

You can use this to ask if data exists or is selected, too:

$res = $DB->query('SELECT COUNT(*) FROM table');
$data_exists = ($res->fetchColumn() > 0) ? true : false;

或使用您的变量:

$res = $DB->query('SELECT COUNT(*) FROM table');
$message = ($res->fetchColumn() > 0) ? array('status' => 'ok') : array('status' => 'error');

这篇关于使用PDO的mysql_num_rows的替代方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！