On 25/02/13 20:14, Joshua TAYLOR wrote:
On Mon, Feb 25, 2013 at 2:15 PM, Joshua TAYLOR <[email protected]> wrote:
On Mon, Feb 25, 2013 at 1:43 PM, Joshua TAYLOR <[email protected]> wrote:
On Mon, Feb 25, 2013 at 11:42 AM, Joshua TAYLOR <[email protected]> wrote:
I'm looking at upgrading a project to use the new 2.10.0 release, and
things are coming along nicely so far (some possible hitches in some
writing code, but can't run tests until I can build...). I've got a
bunch of cases of
UpdateAction.execute(request, getModel(), binding);
that don't compile, though; according to the release notes [1],
"SPARQL Update execution no longer supports setting an initial
binding". I'm going to keep looking for the new way to do this, but
in case someone's got the quick answer prepared, and so that the list
has a recorded answer, I figured I'd ask sooner rather than later:
how can initial bindings be specified in Jena 2.10.0?
[1] http://svn.apache.org/repos/asf/jena/trunk/jena-arq/ReleaseNotes.txt
After some lunch, and some searching, I've found discussion on the dev
list about removing initial bindings [1] and that the accepted way to
do this now is to use BIND or VALUES. In our project, we've
implemented a number of EnhancedResources that perform graph updates
using an idiom where some SPARQL text refers to a ?this variable, and
the execution uses a binding that binds ?this to the enhanced resource
(which might not have a URI). We'd much prefer to do the graph
modification via SPARQL because it involves a number of operations,
and we'd like to be able to use anonymous resources. Here's a typical
example:
static private final UpdateRequest setSomePropertyRequest =
UpdateFactory.create(
"DELETE {\n"+
.... SPARQL code that uses variable ?this ...
"} INSERT {\n"+
"} WHERE {"+
...
"}"
);
public Invocation setSomeProperty( Value value ) {
final QuerySolutionMap binding = new
QuerySolutionMap();
binding.add("?this", this );
UpdateAction.execute( setSomePropertyRequest,
getModel(), binding);
}
return this;
}
Is there still a way to do something like this? If it will involve
using VALUES or BIND, is there a way to make it work with blank nodes?
Thanks in advance,
//JT
[1]
http://mail-archives.apache.org/mod_mbox/jena-dev/201302.mbox/%3CCAPTxtVNWT1HncCLom14cTF0WcjJ04pyP8ALes5Vb5yuSDv8DWw%40mail.gmail.com%3E
Sorry for so much noise, but I wonder if the following is a solution.
This does depend, of course, on the model against which the update is
run being on the same machine, and such. If "this" has a URI, then I
can use the URI in the query, and if it's anonymous, then I can use
the Jena-specific-and-depending-on-local-data id. Then I can use
request.add( "BIND ( ... as ?this )" ) to add the binding constraints
to the request.
final UpdateRequest request = UpdateFactory.create();
// ... more
query in real example
if ( this.isAnon() ) {
request.add( "BIND ( <_:"+this.getId()+"> as
?thisInvocation )" );
}
else {
request.add( "BIND ( <_:"+this.getURI()+"> as
?thisInvocation )" );
}
UpdateAction.execute( request, model ); // executes
with the
requested binding
If this is a solution, it's easy enough to wrap cleanly in a util
method, and I'll be content with that. Can anyone confirm or deny
that this is a solution? (I'm hoping that I understand the
UpdateRequest#add( String ) method correctly. The javadoc [1] is
empty, so I'm going on a guess...)
//JT
[1]
http://jena.apache.org/documentation/javadoc/arq/com/hp/hpl/jena/update/UpdateRequest.html#add(java.lang.String)
Sorry for all the noise and self-replies, but this doesn't work.
UpdateRequest#add doesn't do what I hoped it did. Again, the issue
is, what do we do instead of initial bindings in Jena 2.10.0. We've
been using a bunch of precompiled update requests, and had been able
to provide initial bindings for them. I understand that we should now
be using BIND to introduce bindings, but this will still require some
sort of parameterization (which we did before using initial
bindings). Thoughts?
What about
ParameterizedSparqlString
.asUpdate()
?
--
The technical problem with initial bindings and SPARQL update is what do
they apply to - your examples are one SPARQL Update operation; in
general, a SPARQL Update request may be several operations.
Andy
//JT
