alterar menu principal excerto do código

require_once("../connection.php");

if(!isset($_GET['alterar'])){
 
    $id=$_GET['id'];
    $table="menuprincipal";
    $sql="SELECT * FROM $table WHERE id=$id";
    $query=mysqli_query($connect, $sql) or die($sql);
    $fetch=mysqli_fetch_assoc($query);
}