Re: [Qexo-general] problems aggregating with sum()

[Kevin Y. Kim (Lists)]

On Oct 27, 2005, at 1:30 AM, Per Bothner wrote:
> ...
>
> That is not a well-formed XML file.  At least, it is not a legal
> "XML document", which can have only a single top-level element.
...
> Likewise not valid XML.  It could be valid in the XQuery data model,
> if you view it as a sequence of elements.

Yeah, sorry about that - I was just trying to understand Qexo, and
didn't think about the "well-formedness" of my file(s).

> > Just on a lark, I changed the SUM() to COUNT() - and it does
> > report the correct number of items in the sequence.
>
> The problem is that $recs/value/text() evaluates to a sequence of
> text nodes, and Qexo doesn't know how to convert each text node
> to a number - only to a string.  This has to do with complicated
> XQuery typing rules - which Qexo doesn't implement correctly yet.

Interesting.  I also tried AVG() and that seem to work.  I would
assume that AVG() and SUM() would have to do the same conversion
at some point.  Of course, I know nothing about the internals :-).

> As a work-around try:
>   sum(for $none in $recs/value/text() return number($node))

I assume that should read:
    sum(for $node in $recs/value/text() return number($node))
            ^^^^^- was "$none"
Just wanted to clarify.

Thanks,
-kevin