Proper way to OOP

[Kudose]

Let's say that I have this class that connects to the database and another class that tells me what type of foobars are in the database and various information about them.

What would the proper way to use these two like classes together?

class db {
  function query() ...
}
class foobar extends db {
  function getID(){
    $this->query()...
  }
}

$foo = new foobar;

or

class db {
  function query() ...
}
class foobar {
  var $object;
  function foobar($obj){
    $this->object = $obj;
  }
  function getID(){
    $this->object->query()...
  }
}
$db = new db;
$foo = new foobar($db);

Or am I off?

How would you do this three deep? i.e. db, foo, bar

TIA

[Weedpacket]

Eh, I'd probably have a foobar class that has the db as a property. Chances are that a foobaz class will come along that will also want to use the db, and they might as well share the same connection (or not, as the case may be).

Alternatively, the foobar might end up calling on the resources of something else, and it can only extend one class at a time.

So unless your foobar is a specific kind of db (can you connect to a foobar?), it's not really an extension of the "db" concept.