Rik Hoekstra writes:

A short explanation: sql queries return a result object (so does ZCatalog btw), which you can't address directly in DTML (or at least I wouldn't know how ;-) If it the result object is empty it won't have a (sequence) start in a dtml-in. This is the same code SearchInterfaces uses for returning a 'this query has no results'. "Result" objects behave like sequences. You can ask for their length ("_.len") and access the elements by subscription("[i]"). Of cause, you can use them in "dtml-in".

Dieter