CIBlockProperty::DropColumnSQL

static function DropColumnSQL($strTable, $arColumns)
{
	global $DB;
	$tableFields = $DB->GetTableFields($strTable);
	foreach ($arColumns as $i => $columnName)
	{
		if (!isset($tableFields[$columnName]))
			unset($arColumns[$i]);
	}
	if ($arColumns)
		return array("ALTER TABLE ".$strTable." DROP ".implode(", DROP ", $arColumns));
	else
		return array();
}