Hi Marco -

Are you missing a separator ('\') in your $output variable, or in your `fn:concat($output, '\', 'marco.xml')`?

Here's a similar example that's working for me:

```

declare variable $data := (1, 2, 3, 4);
declare variable $output := '/home/bridger/';

declare function local:process-data(
  $seq as item()*
) as item()* {
  <test created="{fn:current-dateTime()}">
    {
      for $s in $data
      return(
        <item>{$s}</item>
      )
    }
  </test>
};

let $filename := "bridger.xml"
return
  file:write($output || $filename, local:process-data($data))

```

I hope this is helpful!

Best,

Bridger

On Thu, Sep 6, 2018 at 11:13 AM Marco Roling <marcoroling@hotmail.com> wrote:

Dear all,

I am new on the block here, and trying to find my way around BaseX, which seems to meet my needs for my research on digital museum collection data analysis.

I have a very large collection of xml files (> 600000 files) that I am querying, and I want to write the returned result immediately in a file. The following xquery (see below) is not working, which probably comes as no surprise to you all.

But to get me started, I would like to have a simple example that works. Any example would do.

Hope anyone can help me out with this.

Thanks very much, best, Marco.

=====

declare variable $data := collection(PRODRMCollectionItems);

declare variable $output := 'C:\DATAQUERY\BaseX\Q001\outputPROD';

(:This is where all the work is happening:)

declare function local:process-data ($nodes as item()*) as element (root) 

{

  <RMCollectionItemsDATA created="{current-dateTime()}">

  {

     for $a in $nodes//artObjectGetResponse/artObject[objectNumber eq 'NG-NM-1395-A']

       return

        <item>{$a}</item>

  }

  </RMCollectionItemsDATA>

};

(:here we store stuff:)

let $filename := concat($output, "marco.xml")

return

  file:write($filename, local:process-data($data))

=====