public function compile_update( &$query )
	{
		$build = 'update '.$this->escape_table( $query ).' set ';

		// add the array values.
		foreach( $query->values as $key => $value )
		{
			$build .= $this->escape( $key ).' = '.$this->param( $value ).', ';
		}

		$build = substr( $build, 0, -2 );
		$build .= $this->compile_where( $query );
		$build .= $this->compile_limit( $query );

		// cut the last comma away
		return $build;
	}