Works by returning the object that a method is called on after the method does it's work.


<?php
public function from()
{
    if ( 
$this->fromString == '' )
    {
        
$this->fromString 'FROM ';
    }
    
// ...
    
$this->fromString .= join', '$tables );
    return 
$this;
}
?>


Allows for chaining of calls:


<?php
$q
->select'*' )->from'quotes' )
  ->
where$e->eq'author'$q->bindValue'Robert Foster' ) ) );
?>