SQLite3 无法获取列

Question

I wrote my code as simple as possible to make a simple login, because its my first time working with SQLite3 databases.

Here is my code:

<?php
$db  = new SQLite3("FirstDatabase.db");

if (isset($_POST['login'])) {
    $username = $_POST['user'];
    $password = $_POST['pass'];

    $query = $db->prepare("SELECT COUNT(`id`) FROM data WHERE `username` = '$username' AND `password` = '$password'");
    $query->execute();

    $count = $query->fetchColumn();

    if($count = 1){
        echo "Welcome $username!";
    } else {
        echo "Wrong credentials";
    }
}

?>

I'm really confused why this is not working.. I updated all the extensions etc. I know this is vulnerable to pretty much every type of attack, but I'm just trying to figure out the SQLite3 database connection.

Thanks! :)

This is the Error I get btw:

Fatal error: Uncaught Error: Call to undefined method SQLite3Stmt::fetchColumn() in C:\\XAMPP\\htdocs\\PHP-Login\\index.php:41 Stack trace: #0 {main} thrown in C:\\XAMPP\\htdocs\\PHP-Login\\index.php on line 41

Answer 1

The SQL is vulnerable to SQL injection which could be devastating to your database and your system and your health. First and foremost you should change the select to a parametrized query.

There are very good examples in the doc for using a parametrized query and binding the values, not to mention a ton of resource on this site.

The error is telling you that that there is not method fetchColumn() for a SQLite3Stmt object. The PHP: SQLite3Stmt doc confirms that. It is a method on the PDO database extension.