[Zope-dev] ZCatalog comments

[Dieter Maurer]

Chris Withers writes:
 > > +            - an empty query mapping (or a bogus REQUEST) returns all
 > > +              items in the
 > > +            catalog.
 > 
 > Is it only me that finds this really irritating? Surely a blank query mapping
 > should return nothing, not everything?
 > (at the least it'd be nice if this was configurable ;-)
No! Please not!

It is very natural that an empty query returns everything
when subqueries are combined with "AND".

   Any time, you add a subquery, the result set is a subset of the former
   one. For this to work out without boundary exceptions
   (we all hate them, I hope!), the empty query must be the complete
   set.

Of course, if subqueries are combined with "OR", the empty
query should return no hits....

 > > +        Depending on the type of index you are querying, you may be
 > > +        able to provide more advanced search parameters that can
 > > +        specify range searches or wildcards.  These features are
 > > +        documented in The Zope Book.
 > 
 > Wildcards? Hmmm... that's enticing, where and how will they be supported? 
Did you look in the Zope Book?

  The section above says, your question would be answered there.



Dieter