XQuery count()

[Wolfgang Meier]

Hi,

> I need to count the total number of distinct collections in my db (eXist XML
> Database).
> How can i do this in a compact way using XQuery?

This won't be possible without using extension functions. Different
systems will have different ideas of what constitutes a "collection"
(which can be queried with fn:collection). In eXist, you could use a
recursive approach:

import module namespace xdb="http://exist-db.org/xquery/xmldb";

declare function local:scan-collection($collection) {
  $collection,
  for $child in xdb:get-child-collections($collection) return
local:scan-collection(concat($collection, "/", $child))
};

local:scan-collection("/db")

The following solution is much shorter, but it might be slower:

distinct-values(
  for $doc in collection("/db")
  return util:collection-name($doc)
)

Wolfgang