protected function _process( $stmt )
	{
		$table = 'madmin_log';

		$this->_msg( 'Changing site ID to NULL in madmin_log', 0 );
		$this->_status('');

		$this->_msg(sprintf('Changing table "%1$s": ', $table), 1);

		if( $this->_schema->tableExists($table) &&
			!$this->_schema->getColumnDetails( $table, 'siteid' )->isNullable() )
		{
			$this->_execute( $stmt );
			$this->_status( 'done' );
		} else {
			$this->_status( 'OK' );
		}

	}