PHP Llamada constante en clase

//it's possible to declare constant in base class, and override it in child, and access to correct value of the const from the static method is possible by 'get_called_class' method:
<?php
abstract class dbObject
{   
    const TABLE_NAME='undefined';
   
    public static function GetAll()
    {
        $c = get_called_class();
        return "SELECT * FROM `".$c::TABLE_NAME."`";
    }   
}

class dbPerson extends dbObject
{
    const TABLE_NAME='persons';
}

class dbAdmin extends dbPerson
{
    const TABLE_NAME='admins';
}

echo dbPerson::GetAll()."<br>";//output: "SELECT * FROM `persons`"
echo dbAdmin::GetAll()."<br>";//output: "SELECT * FROM `admins`"

?>
Dentetsu