<?php

require_once('../conn.php');

$accountid = $_GET['user_id'];

$sql_str = "SELECT name FROM account WHERE accountid = :accountid";
$stmt = $conn->prepare($sql_str);
$stmt->bindParam(':accountid', $accountid);
$stmt->execute();
$user = $stmt->fetch(PDO::FETCH_ASSOC);
echo $user['name'];