Sure, but you'd still need to connect and interface with the SQL implementations - the queries themselves are the smaller piece of the work if you want to support several different database backends.
> the queries themselves are the smaller piece of the work if you want to support several different database backends.
Not if you use something like the Delphi / Lazarus model with pluggable drivers and direct SQL capability (and stick to whichever variant of ANSI-standard SQL your intended backends have in common).