You have to set a listener that will read the new changes on db or from the interface where u are setting the data for the database call the fb api and post it inmediatly... in that case would be something like this.
$autpost = array('message' => ' message',
'name' => 'This is my demo',
'caption' => "Caption ",
'link' => 'http://facebook.com',
'description' => 'description',
'picture' => 'http://somesite.picture.jpg',
'actions' => array(array('name' => 'Get Search',
'link' => 'http://www.google.com'))
);
$result = $facebook->api('/fanpage id/feed/', 'post', $wall_post);