This should be easy

url_domain || url_path || url_query_params  as request

really should work.

BUT if any one of these is null it will deliver a null string

So you need

nvl(url_domain,”) || nvl(url_path,”) || nvl(url_query_params,”) as request

This replaces a Null with a blank.

Why can’t it do this anyway? Who knows.