简单的PHP更新查询

Question

I have a form which should check the posted field and update an associated row in a sql table incrementally i.e. the number should increase each time. I've tried this a few different ways but unable to get this working - any help appreciated.

if(!empty($_POST['username']))
{
    $username =($_POST['username']);
    mysql_query("
        UPDATE users 
        SET refer = refer +1
        WHERE Username = '".$username."'
    ");
}

Answer 1

I recomend you use the php 7 and PDO, the mysql_query its obsolete :

Make something like:

$pdo = new PDO('mysql:host=localhost;dbname=database', 'user', 'password');

if (!empty($_POST['username'])) {
$stmt = $pdo->prepare("UPDATE users SET refer = :refer WHERE Username = :username");

$stmt->execute([
    'refer' => refer + 1,
    'username' => $_POST['username']
]);
}