Add files via upload

gamerevs/check_username.php

@@ -0,0 +1,35 @@
+<?php
+// check_username.php
+
+$host = 'localhost';
+$db   = 'game_review_website';
+$user = 'root'; 
+$pass = '';     
+
+$conn = new mysqli($host, $user, $pass, $db);
+
+if ($conn->connect_error) {
+    die('Connection failed: ' . $conn->connect_error);
+}
+
+if (isset($_GET['username'])) {
+    $username = trim($_GET['username']);
+
+    // Prepare statement to prevent SQL injection
+    $stmt = $conn->prepare('SELECT id FROM users WHERE username = ?');
+    $stmt->bind_param('s', $username);
+    $stmt->execute();
+    $stmt->store_result();
+
+    // If username exists, output 'taken', else 'available'
+    if ($stmt->num_rows > 0) {
+        echo 'taken';
+    } else {
+        echo 'available';
+    }
+
+    $stmt->close();
+}
+
+$conn->close();
+?>