Hi all, Maybe this is related to http://xqj.net/basex/ instead of BaseX itself, but as I don't know allow me to ask here first. Whenever I have somehow locked a BaseX database, like by using the standalone command line utility or the GUI, then I get something like the following in the BaseX log files: QUERY(1) for $c in collection('factbook')//country[name='Albania']return( replace value of node $c/@population with xs:integer($c/@population + 1)) OK 39.92 ms QUERY(1) OK 0.62 ms FULL(1) Error: [BXDB0007] Database 'factbook' is opened by another process. CLOSE(1) OK 39.68 ms Good. However, I don't see that error in my Java code. The Java code just continues like all was fine. Can I somehow make the Java code fail when this happens? See example below, and the same thing in the attachment. Thanks, Arjan. private static final String DRIVER = "net.xqj.basex.BaseXXQDataSource"; private static final String SELECT = "xs:long(collection('factbook')//country[name='Albania']/@population[1]/data(.))"; private static final String UPDATE = "for $c in collection('factbook')//country[name='Albania']" + "return(" + " replace value of node $c/@population with xs:integer($c/@population + 1)" + ")"; @Test public void testUpdate() { try { XQDataSource xqd = (XQDataSource) Class.forName(DRIVER) .newInstance(); XQConnection xqc = xqd.getConnection("admin", "admin"); XQExpression xqe = xqc.createExpression(); XQSequence xqs = xqe.executeQuery(SELECT); xqs.next(); long before = xqs.getLong(); System.out.println("Initial value: " + before); System.out.println("Updating..."); xqs = xqe.executeQuery(UPDATE); xqs = xqe.executeQuery(SELECT); xqs.next(); long after = xqs.getLong(); System.out.println("Resulting value: " + after); xqc.close(); Assert.assertEquals("Update should have succeeded or failed", before + 1, after); } catch (Exception e) { e.printStackTrace(); } }