CSqlUtil::AddToFrom

static function AddToFrom(&$arField, &$arJoined, &$strSqlFrom)
{
	if (isset($arField["FROM"])
		&& $arField["FROM"] <> ''
		&& !in_array($arField["FROM"], $arJoined))
	{
		if ($strSqlFrom <> '')
			$strSqlFrom .= " ";
		$strSqlFrom .= $arField["FROM"];
		$arJoined[] = $arField["FROM"];
	}
}