PHP MySQLi function get user data can't work - php

Question

i am using This code for showing user data record but this code is not work on my side
I want to echo out specific user data. I created a function where I insert multiple arguments (each argument represents a column in the database) and then echo whichever column I want with a simple line of code.
Index.php
include('function.php');
$conn = new MySQLi(localhost, root, password, database);
$user_id = $_SESSION['login_user']; // like 1
$user = user_data($conn, $user_id, 'login', 'pass', 'nikename', 'email');
if(empty($user)){
echo 'error'; // always showing this error
}else{
echo $user['nickename'];
}
Always Showing echo 'error';
function user_data($conn, $user_id){
$data = array();
$user_id = (int)$user_id;
$func_num_args = func_num_args();
$func_get_args = func_get_args();
if ($func_num_args > 1) {
unset($func_get_args[0]);
unset($func_get_args[1]);
$valid = array('login', 'pass', 'nikename', 'email');
$fields = array();
foreach($func_get_args as $arg) {
if(in_array($arg, $valid)) $fields[] = $arg;
}
$fields = '`' . implode ('`, `', $fields) . '`';
if($stmt = $conn->prepare("SELECT $fields FROM `users` WHERE `user_id` = ?")) {
$stmt->bind_param('si', $fields, $user_id);
$stmt->execute();
//here I am trying to convert the result into an array
$meta = $stmt->result_metadata();
while ($field = $meta->fetch_field()) {
$parameters[] = &$row[$field->name];
}
call_user_func_array(array($stmt, 'bind_result'), $parameters);
while ($stmt->fetch()) {
foreach($row as $key => $val) {
$x[$key] = $val;
}
$results[] = $x;
}
return $results;
$stmt->close();
}
}
}

Answer 1

Seeing and analyzing your code several times, I think the below will solve your issue.
Add this before your while/fetch loop
$row = array();
stmt_bind_assoc($stmt, $row);
so your code will look like this
$row = array();
stmt_bind_assoc($stmt, $row);
while ($stmt->fetch()) {
foreach($row as $key => $val) {
$x[$key] = $val;
}
$results[] = $x;
}
Also make sure you read the full documentation of bind_param on php.net here
Thanks and Best Regards

Answer 2

I guess, instead of
if($stmt = $conn->prepare("SELECT $fields FROM `users` WHERE `user_id` = ?")) {
$stmt->bind_param('si', $fields, $user_id);
you should go with
if($stmt = $conn->prepare("SELECT $fields FROM `users` WHERE `user_id` = ?")) {
$stmt->bind_param('i', $fields, $user_id);
Bind parameters. Types: s = string, i = integer, d = double, b = blob
As far as you have one argument with type INT you need to pass 'i' as a first parameters.
Try debugging over line by line in that function where you will get exact flaw by var_dump().