Hi Will,

I don't know of a simple way to do exact what you're requesting. However, in a custom query you could do a CASE WHEN UrlColumn IS NOT NULL THEN 'Go to Site' ELSE NULL END to conditionally show the link text. Additionally, you could create your own Edit column that points to the same URL that the default list UI uses.

Alternatively, you could use XML query metadata to configure your URL column point to a <displayColumnFactory> of your own creation (a Java class that implements org.labkey.api.data.DisplayColumnFactory) that does your desired rendering behavior.

Thanks,
Josh