使用XQuery和BaseX将更新写入xml文件

Question

I have a file.xml storing protocols whose structure is the following:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<economato> 
  <protocollo>
    <numero>1</numero>
    <data>2014-12-15</data>
    <oggetto>Trasmissione prospetti di rendiconto chiusura esercizio 2012 - beni mobili proprietà dello stato</oggetto>
    <destinatario>Ragioneria Provinciale Como</destinatario>
    <operatore>MAESTRI</operatore>
    <valido>true</valido>
  </protocollo>
  ...
</economato>

and I would need to change/update the value of the tag "valido", for example from 'true' to 'false' of the protocollo number 1 and I would like this update to be written into the file. As I am using BaseX, following the documentation I have tried to write this query:

xquery let $update := doc('C:\Users\Lorenzo Enzino  Vinci\Desktop\ECONOMATO\databases\2014.xml')//economato/protocollo[numero = 1] return replace value of node $update/valido with 'false' into doc('C:\Users\Lorenzo Enzino Vinci\Desktop\ECONOMATO\databases\2014.xml')//economato

but I get an error like

[XPST0003] Unexpected end of query: 'into doc('C:\Users\Lorenzo Enzino Vinci\Desktop\ECONOMATO\databases\2014.xml')//economato'

So my query is wrong but I do not know where. Can you help me?

Answer 1

It fails, because it is invalid XQuery Update syntax. There is not replace ... with ... into ... command, there only is replace ... with ... , as the error message already indicates. It would also be unlogical, because $update already holds a reference to the correct xml fragment.

So you simply have to use the following XQuery:

let $update := doc('C:\Users\Lorenzo Enzino  Vinci\Desktop\ECONOMATO\databases\2014.xml')//economato/protocollo[numero = 1]
return replace value of node $update/valido with 'false'

Also, please note that updates are not automatically written back to files in the file system (to avoid accidentally overwriting files), eg by starting it with basex -u . This is explained in detail in the BaseX wiki