So far BaseX differentiates between fragments and database nodes. Updates on fragments
have no effect on any existing databases and are therefore not applied at all. This
includes the test for violation of any testing constraintsas well. Thus it It is therefor possible to execute an
update on a fragment, which would raise an error if applied on a database node.
:File 'doc.xml': <pre><n id='1'/></pre>
:<pre>insert node attribute id{'0'} into doc('doc.xml')//n</pre>
:Result: <codepre style='color:red'>[XUDY0021] Duplicate attribute "id".</codepre>
===Fragments & fn:put()===