Question

When I run this code:

<?php
require_once 'getdata.class.php';
class Header extends GetData
{ 
    public $headers;

    public function sayfaHeader($sayfa = 1) 
    { 
        return parent::$sql = "SELECT * FROM header WHERE id='" . $sayfa . "'"; 
        //$data = parent::getData();
        return $data;
        $this->headers = (object) $data;
        return (object) $this->headers;
    } 
} 
$header = new Header;
echo $header->sayfaHeader();

?>

I get this error code:

Fatal error:  Access to undeclared static property: GetData::$sql in C:\AppServ\www\ilk\class\header.class.php on line 9

Why I can’t use parent:: word?
I want to only change variable value of public $sql

Answer 1

We should see GetData parent class, at least. I bet $sql is not a static property in that class. In that case, if it makes sense to be static, declare it static, else replace:

parent::$sql = "SELECT * FROM header WHERE id='" . $sayfa . "'";

With:

$this->sql = "SELECT * FROM header WHERE id='" . $sayfa . "'";

Any object can always access to properties declared public or protected in parent class. You don’t need parent:: in that case.

BTW I don’t understand why you have all these return statements…