The root of is that the command line --namegraph does not make sure URIs
are resolved and it looks like it used to.
Oddly, if you don't use PREFIX :<.> it is hard to tell as the base URI
is used to create table items and so relative URIs reappear.
Doing
SELECT ?s ?p ?o ?g (str(?g) As ?G) {...}
shows the URI string without abbreviation.
Andy
On 10/07/18 13:06, ajs6f wrote:
Some RDF serializations, like Turtle, can declare a base for relative URIs.
Since you are using Turtle (based on the .ttl extensions shown in your
filenames) perhaps this can serve you:
https://www.w3.org/TR/turtle/#relative-iri
ajs6f
On Jul 9, 2018, at 5:51 PM, Michal Rohacek <[email protected]> wrote:
Hi there,
thank you for your quick support!
I changed all the URIs to absolute URIs (full file path in format
"file:///C:/path/to/file/ds-ng-1.ttl") and now it works - in windows cmd,
as well as in Java code.
My question is, is this the only way for me to execute this kind of
queries, or is there a solution which makes me able to use the "relative"
URIs in cases like this one? Is there any fix to force the program to
expand the URI or whatever - simply, for me, to be able to use these
features like it is being used in the tutorial?
Just because this :
sparql.bat --graph dft.ttl --namedgraph 1.ttl --namedgraph 2.ttl --query
q.rq
is much more compact and tidy like this one:
sparql.bat --graph dft.ttl --namedgraph
file:///C:/very/long/and/awful/path/to/file/1.ttl --namedgraph
file:///C:/very/long/and/awful/path/to/file/2.ttl --query q.rq
Thank you in advance.
Michal
2018-07-09 22:42 GMT+02:00 Andy Seaborne <[email protected]>:
Michal,
It looks like the use of "--namedgraph" isn't expanding the URI
In "--namedgraph ds-ng-1.ttl", "ds-ng-1.ttl" isn't an absolute URI and it
isn't being expanded. If it had, it would be file:///whatever/ds-ng-1.ttl
and because <.> is really <file:///whatever/> it would be abbreviated.
A work aroung is to use file://$PWD/ds-ng-1.ttl (Linux, MacOS) or the
Windows equivalent.
When a query is parsed, GRAPH :ds-ng-1.ttl is expanded.
You might find it helpful to try the queries without "PREFIX : <.>" so
the full URIs are printed.
If you get FILE in the --namedgraph FILE to be the absolute URI (same
characters) then the abbreviation should work.
Andy
On 08/07/18 22:57, michal.r.256 wrote:
Good evening,
I am trying to get through the tutorial (I am beginner) and I am
experiencing unexpected behavior of these queries (even if Im copypasting
the tutorials):
Here is the link to referenced tutorial page:
https://jena.apache.org/tutorials/sparql_datasets.html
First attempt, this query works fine:
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX : <.>
SELECT *
{ ?s ?p ?o }
Results:
----------------------------------------------------------------------
| s | p | o |
======================================================================
| :ds-ng-2.ttl | dc:date | "2005-09-22T05:53:05+01:00"^^xsd:dateTime |
| :ds-ng-1.ttl | dc:date | "2005-07-14T03:18:56+01:00"^^xsd:dateTime |
----------------------------------------------------------------------
Second, this works pretty good too:
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX : <.>
SELECT *
{
{ ?s ?p ?o } UNION { GRAPH ?g { ?s ?p ?o } }
}
Results not absolutely the same (the referenced named graph names are not
exactly the same in the first and the third column (the colon missing and
the <> instead), and I was not able to change this, although I was trying
pretty hard as I thought that there could be the cause of my issue)
------------------------------------------------------------
---------------------------------
| s | p | o |
g |
============================================================
=================================
| :ds-ng-2.ttl | dc:date | "2005-09-22T05:53:05+01:00"^^xsd:dateTime |
|
| :ds-ng-1.ttl | dc:date | "2005-07-14T03:18:56+01:00"^^xsd:dateTime |
|
| _:b0 | dc:title | "Harry Potter and the Chamber of Secrets" |
<ds-ng-1.ttl> |
| _:b1 | dc:title | "Harry Potter and the Philospher's Stone" |
<ds-ng-1.ttl> |
| _:b2 | dc:title | "Harry Potter and the Sorcerer's Stone" |
<ds-ng-2.ttl> |
| _:b3 | dc:title | "Harry Potter and the Chamber of Secrets" |
<ds-ng-2.ttl> |
------------------------------------------------------------
---------------------------------
Now, this query is the first that doesnt work at all:
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX : <.>
SELECT ?title
{
GRAPH :ds-ng-2.ttl
{ ?b dc:title ?title }
}
Results are blank all the time:
---------
| title |
=========
---------
Same result with this query:
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX : <.>
SELECT ?date ?title
{
?g dc:date ?date . FILTER (?date > "2005-08-01T00:00:00Z"^^xsd:dateTime
)
GRAPH ?g
{ ?b dc:title ?title }
}
I have tried many things I googled out (but no exact solution for this
problem) and nothing worked, I have no idea what could be wrong.
Thanks for every support.
