xquery | Extract data or evaluate value | Parser library

In the XQuery Spec https://www.w3.org/TR/xquery-31/#id-order-by-clause it is explained as

For the purpose of determining their relative position in the ordering sequence, the greater-than relationship between two orderspec values W and V is defined as follows:

When the orderspec specifies empty least, the following rules are applied in order:

If V is an empty sequence and W is not an empty sequence, then W greater-than V is true.

If V is NaN and W is neither NaN nor an empty sequence, then W greater-than V is true.

If a specific collation C is specified, and V and W are both of type xs:string or are convertible to xs:string by subtype substitution and/or type promotion, then:

If fn:compare(V, W, C) is less than zero, then W greater-than V is true; otherwise W greater-than V is false.

If none of the above rules apply, then:

If W gt V is true, then W greater-than V is true; otherwise W greater-than V is false.

When the orderspec specifies empty greatest, the following rules are applied in order:

If W is an empty sequence and V is not an empty sequence, then W greater-than V is true.

If W is NaN and V is neither NaN nor an empty sequence, then W greater-than V is true.

If a specific collation C is specified, and V and W are both of type xs:string or are convertible to xs:string by subtype substitution and/or type promotion, then:

If fn:compare(V, W, C) is less than zero, then W greater-than V is true; otherwise W greater-than V is false.

If none of the above rules apply, then:

If W gt V is true, then W greater-than V is true; otherwise W greater-than V is false.

Basically, if an expression used in an order by clause gives an empty sequence for an item to be ordered, the empty least declares to sort it before items that have a non-empty sort key while empty greatest sort it after those items.

A simple example:

The XQuery

Configure the job with the PROCESS-TASK option to use the com.marklogic.developer.corb.ExportBatchToFileTask class, which will write the results of each process module invocation to an output file. You can configure where to write the file and the filename with EXPORT-FILE-NAME and EXPORT-FILE-DIR options. If you don't configure the EXPORT-FILE-DIR and just give it a filename with EXPORT-FILE-NAME it writes relative from where CoRB is launched.

Due to the grouping you already have, count($elems) will have the right value in the return clause.

I think you original use of the let $sep is causing problems, the grouping count($elems) I suggested works fine for me at https://xqueryfiddle.liberty-development.net/bFDbxm7 where I have moved the $sep to a declared variable.

I am using BaseX v.9.5.2

XQuery

The CoRB StreamingXPath is not currently able to register and leverage namespaces and namespace-prefixes, so the XPath targeting namespace-qualified elements can't leverage namespace-prefixes.

A more generic match on the document element with a predicate filtering by local-name() will work though. It's a little ugly and a lot more typing, but works:

If you want a row for each author, then create a row for each author:

XSLT 1.0

similar to my answer for https://www.biostars.org/p/280581/ using my tool xsltstream:

Please try the following solution.

It is a minimal reproducible example. You copy it to SSMS as-is, and it works.

It handles the default namespace via WITH XMLNAMESPACES clause.

SQL

You're correct that doing what I call deep update of a map is quite difficult with XQuery 3.1 (and indeed XSLT 3.0) as currently defined. And it's not easy to define language constructs with clean semantics. I attempted to design a construct as an XSLT extension instruction - see https://saxonica.com/documentation10/index.html#!extensions/instructions/deep-update -- but I don't think its anywhere near a perfect solution.