Trying to get property of non-object: Using SELECT - php

Question

I got little problem with my code... because I try to SELECT sth from database and then INSERT some value to another table, but in normal code from w3school
and I got error
Tryingo to get property of non-object
Here is my code:
<?php
session_start();
function connectionDB(){
$host = "localhost";
$username = "root";
$password = "";
$db_name = "project";
$conn = new mysqli($host, $username, $password, $db_name);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
return $conn;
}
function getID(){
$id = $_GET['id'];
return $id;
}
$login =$_SESSION['login'];
$conn =connectionDB();
$idCar = getID();
echo $idCar;
$sqluser = "SELECT ID_USER FROM login_table WHERE LOGIN = $login";
if($result->num_rows > 0)
$result = $conn->query($sqluser);
{
while($row = $result->fetch_assoc())
{
$sql = "INSERT INTO cart (id_user) VALUES ('".$row['ID_USER']."')";
}
}else echo"error";
?>
THIS IS THE CODE OF SIDE WITH PRODUCT

Answer 1

Please see change near your IF loop
$sqluser = "SELECT ID_USER FROM login_table WHERE LOGIN = $login";
$result = $conn->query($sqluser); //check result first
if($result->num_rows > 0) //get number of rows
{
while($row = $result->fetch_assoc())
{
$sql = "INSERT INTO cart (id_user) VALUES ('".$row['ID_USER']."')";
}
}else echo"error";