CLearnLesson::LessonIdByChapterId

static function LessonIdByChapterId ($chapterId)
{
	$rc = self::GetListUni(
		array(),
		array(
			'WAS_CHAPTER_ID'    => $chapterId,
			'CHECK_PERMISSIONS' => 'N'
		),
		array('LESSON_ID'),
		self::GET_LIST_ALL
	);

	if ($rc === false)
		throw new LearnException ('EA_UNKNOWN_ERROR', LearnException::EXC_ERR_ALL_GIVEUP);

	$row = $rc->Fetch();
	if ( ! isset($row['LESSON_ID']) )
		return (false);
	else
		return ( (int) $row['LESSON_ID'] );
}