CheckListTable::moveAfterItem

static function moveAfterItem($templateId, $selectedItemId, $insertAfterItemId)
{
	$templateId = 			Assert::expectIntegerPositive($templateId, '$templateId');
	$selectedItemId = 		Assert::expectIntegerPositive($selectedItemId, '$selectedItemId');
	$insertAfterItemId = 	Assert::expectIntegerPositive($insertAfterItemId, '$insertAfterItemId');

	$res = static::getList(array('filter' => array(
		'=TEMPLATE_ID' => $templateId
	), 'order' => array(
		'SORT' => 'asc',
		'ID' => 'asc'
	), 'select' => array(
		'ID',
		'SORT'
	)));

	$items = array($selectedItemId => 0);	// by default to first position
	$prevItemId = 0;
	$sortIndex = 1;
	while($item = $res->fetch())
	{
		if ($insertAfterItemId == $prevItemId)
			$items[$selectedItemId] = $sortIndex++;

		if ($item['ID'] != $selectedItemId)
			$items[$item['ID']] = $sortIndex++;

		$prevItemId = $item['ID'];
	}

	if ($insertAfterItemId == $prevItemId)
		$items[$selectedItemId] = $sortIndex;

	if (!empty($items))
	{
		$sql = "
			UPDATE ".static::getTableName()."
				SET
					SORT = CASE ";

		foreach ($items as $id => $sortIndex)
			$sql .= " WHEN ID = '".intval($id)."' THEN '".intval($sortIndex)."'";

		$sql .= " END

			WHERE TEMPLATE_ID = '".intval($templateId)."'";

		BitrixMainHttpApplication::getConnection()->query($sql);
	}
}