Check if ID exist in database

check_id_exist.php

<?php
$mysql_server = "localhost";
$mysql_user = "username";
$mysql_password = "password";
$mysql_dbname = "db";

$mysqlcon = new mysqli($mysql_server, $mysql_user, $mysql_password, $mysql_dbname);
if ($mysqlcon->connect_error) {
    die("Connection failed: " . $mysqlcon->connect_error);
} 

$id = mysqli_real_escape_string($mysqlcon,$_GET['id']);
$query = "SELECT id FROM members WHERE id='$id'";

if ($mysqlcon->query($query) != TRUE) {
    echo "Error: " . $query . "<br>" . $mysqlcon->error;
}

if ($result = mysqli_query($mysqlcon, $query))
{

    $row_cnt = mysqli_num_rows($result);

    if($row_cn > 0)
    {
        echo "The ID ".$id." is found in database (exist)";
    }
    else
    {
        echo "The ID ".$id." is not found in database (not exist)";
    }
    mysqli_free_result($result);
}

mysqli_close($mysqlcon);
?>