xquery version "1.0";

declare namespace file = "http://exist-db.org/xquery/file";
declare namespace xmldb = "http://exist-db.org/xquery/xmldb";
declare namespace xslfo = "http://exist-db.org/xquery/xslfo";

let $fo := fn:doc('/db/test-fo.xml')
let $pdf := xslfo:render($fo, "application/pdf", (), ())
return
  xmldb:store("/db", "result.pdf", $pdf, "application/pdf")