Migrating from Cf2016 to CF2018 I discovered that CFQUERY of query results no longer support using ordinals in the order by clause.  For example,

<cfquery name=”getroles” dbtype=”query”>
select distinct role, role_action, sort_order
from approvers
order by 3
</cfquery>

would sort the selection by the field sort_order up to and including CF2016.  This has to be rewritten to work in CF2018 as

<cfquery name=”getroles” dbtype=”query”>
select distinct role, role_action, sort_order
from approvers
order by sort_order
</cfquery>

I was unable to  find any reference to this searching the web.  Hope it helps someone.