PHP Function to validate setting

PHP
18

Needs to be $dsn = 'mysql:dbname=dev;host=127.0.0.1';
Don’t replace dbname because that is how you connect to your database. It’s equivalent to procedural mysqli_*'s prepare($db, ..) where $db is the database you want to use.

Also, you should take note that square bracket arrays [] are available only from PHP 5.4 +. So don’t use square bracket arrays [] if you have PHP 5.3. You’ll get an error. Use array(); as an alternative if you have PHP 5.3 and below.

The reason why they are passing the $pdo/db variable is because in PHP, you don’t really want to create a new database connection every time you do a query. It’s easier to re-use the connection then closing it and re-opening it. In a way, it’s kind of like how system admins are with up-time.

You don’t need to. You can still use OOP mysqli_*.

<?php
// Connect to MySQL
$host = '127.0.0.1';
$username = 'dev';
$password = 'dev.dev';
$db = 'dev';

$mysqli = new mysqli($host, $username, $password, $db);
if($mysqli->connect_errno) {

    die('Do not display any errors here. You should NEVER display errors to the user.');

}

$sql = 'SELECT 1 FROM flags WHERE flagname = ? AND ? BETWEEN MIN(flagvalue) AND MAX(flagvalue) LIMIT 1';
$prepare = $mysqli->prepare($sql);
$prepare->bind_param('ss', $flagname, $flagname2);
$prepare->execute();
$prepare->store_result();

if($prepare->num_rows) {

    $prepare->bind_result($first_flag);

    while($prepare->fetch()) {

        print($first_flag);

    }

} else {

    print('No record with that information');

}

Also take note, you should always be using num_rows and rowCount() as it helps prevent white pages (nothing is displayed, no errors, no warning, nothing) and prevents error warning. It is also helps better user experience.

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