SQL generates 'access violation or syntax' error whencompiled into string var ahead of time

[mate of the state]

I have stumbled across something perplexing and frustrating, and I'm hoping
somebody can shed some light here.

I have a site with some listings. I would like to give the users the ability
to filter out items from those listings based on certain criteria. They may
select all, none or some of the filters. As such, I would like to create the
query programmatically based upon which filters they're applying.

See the attached code for some insight into what I'm talking about.

Without any filters supplied, the query should be very simple:

SELECT * FROM auctions WHERE auctions.end > #createODBCDateTime(now())#

This should simply return all auctions that have no yet closed, and it DOES as
long as I put that text as the body of a <CFquery /> but NOT when I put it into
a variable first, and then use that within' <CFquery />

What's at play here? Surely ColdFusion is not so unfairly maligned as to now
allow programmatic construction of queries as I've discussed here!

[OldCFer]

Use:
<CFquery name="auctions" datasource="#request.dsn#">#PreserveSingleQuotes(a q)#</CFquery>

[mate of the state]

Ah! Beautiful! Thanks! :)