[xquery-talk] Questions on User-Defined Functions

[Wei, Alice J.]

Hi, XQueriers:

  I have here one debugging issue here with XQuery using User-Defined Function.

  This is what I have now:

declare function local:total($po as element(statistics))
      as xs:integer {
   count($po)
};
local:total(collection("xmldb:exist://db/my")//ad)

The error I got is:

Error while evaluating expression: declare function local:total($po as element(statistics)) as xs:integer { count($po) }; local:total(collection("xmldb:exist://db/cbml")//ad). The actual cardinality for parameter 1 does not match the cardinality declared in the function's signature: local:total($a as element) xs:integer. Expected cardinality: exactly one, got 517. [at line 115, column 21] In call to function: local:total(element) [5:1]

The code is based on the XQuery of

<statistics>
{count(distinct-values((
fn:collection("xmldb:exist://db/my"))//ad))}
</statistics>

which brings the output of  <statistics>229</statistics>

What have I done wrong here?

 The other question I have is that since I intend to create a web application out of XQuery, whether or not I should use user-defined functions. Any suggestion is welcome.

Alice
======================================================
Alice Wei
MIS 2008
School of Library and Information Science
Indiana University Bloomington
ajwei at indiana.edu