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' ) ) );
?>