I am working on a personal project using PHP and RDF4J Workbench Service and I have a repository with 3 contexts, one for robot categories, one for those robots that belongs to these categories and another one in which I store the owl:sameAs property to wikidata identifiers for the initial data.
The problem is that a user can insert robots and the new inserted ones will not be linked to wikidata identifiers but instead will have unique URI's resulted by just removing the extra-space and concatenating the name that user had inserted. Now, when I query for the data I need, I want all these robots to be shown, but if my query is as it follows:
PREFIX : <http://example.com#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX wd: <http://www.wikidata.org/entity/>
SELECT ?name ?image ?releaseDate ?skills ?manufacturer ?mass
WHERE {
{ SELECT ?robot ?image ?releaseDate ?skills ?manufacturer ?mass
WHERE {
<http://example.com#EducationalRobots> a :Category; :hasRobots [:idRobot ?x] .
?x owl:sameAs ?robot .
?x :hasImage ?image .
?x :releaseDate ?releaseDate .
?x :hasSkills ?skills .
?x :manufacturer ?manufacturer.
?x :hasMass ?mass
}
}
SERVICE <https://query.wikidata.org/sparql> {
?robot rdfs:label ?name .
FILTER(lang(?name)="en")
}
}
in the end I will only get the initial statements I inserted, those that do have a wikidata identifier linked. So I was thinking of maybe making the difference in the backend, using an if statement where I can ASK if the items from the requested category have an identifier and if so do a specific query, the one from above, else just replace the query and retrieve the local URI. But isn't there a way of doing this directly in the query, so the code will look much cleaner ? Such as SELECT IF statement or so. I am not familiar with advanced query practices and I would appreciate any advice.
Snippet of the graph:
Request:
function getDetails(id) {
//console.log(id);
let url = "query.php";
$.ajax({
type: "POST",
url:url,
data: {"id": id },
success: function (response){
let final = JSON.parse(response);
console.log(final.results);
$('#tableId').find('tbody')
.empty();
final.results.bindings.forEach((item, index)=>{
console.log(item);
if (item.name) {
s = item.name;
id = s.split(" ").join("");
$('#tableId').find('tbody')
.append($(`<tr id=${id} class="border_bottom">`)
.append($('<td class="mt-3 text-center">')
.append(`<p class='mt-4'><b><i>${item.name.value} </i></b></p><br><button class='btn btn-danger' id='${item.name.value}' onclick="deleteMovie(this.id, '${id}')">Delete</button></div>`)
)
.append($('<td class="text-center">')
.append($('<img height="150" width="250">')
.attr('src', 'images/'+item.image.value)
)
)
.append($('<td>')
.append($('<small> Manufacturer: </small><p>'+ item.manufacturer.value+ '</p><small>Release date: </small><p>' + item.releaseDate.value +'</p><small>Skills: </small><p>'+item.skills.value +'</p><small> Mass: </small><p>'+item.mass.value + ' kg</p>'))
)
)
}
})
}
});
}
And in the backend I'm working with EasyRdf\Sparql\Client:
<?php
$id = $_POST['id'];
require 'vendor/autoload.php';
$address = "http://localhost:8080/rdf4j-server/repositories/graph?query=";
$query = "PREFIX : <http://example.com#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX wd: <http://www.wikidata.org/entity/>
SELECT ?name ?image ?releaseDate ?skills ?manufacturer ?mass
WHERE { { SELECT ?robot ?image ?releaseDate ?skills ?manufacturer ?mass WHERE {<".$id."> a :Category; :hasRobots [:idRobot ?x] . ?x owl:sameAs ?robot . ?x :hasImage ?image . ?x :releaseDate ?releaseDate . ?x :hasSkills ?skills . ?x :manufacturer ?manufacturer. ?x :hasMass ?mass} } SERVICE <https://query.wikidata.org/sparql> { ?robot rdfs:label ?name . FILTER(lang(?name)=\"en\") } }";
$qry = urlencode($query);
// print $qry;
$client = new EasyRdf\Http\Client($address.$qry);
$client->setHeaders("Accept","application/sparql-results+json");
$resultJSON = $client->request()->getBody();
// print $resultJSON;
$finalResult = new EasyRdf\Sparql\Result($rezultatJSON,"application/sparql-results+json");
// print $finalResult;
return $finalResult;
Thank you !
