Sparql query to get the original triples

[fburdet]

Hello,

What would be the sparql query to run in blazegraph to get back all the triples that correspond to a rule?

Thanks in advance!

[matthias-samwald]

@nomisto ?

[fburdet]

If possible with the labels ;)

[nomisto]

Hello @fburdet,

As different rules require different sparql queries there is not a single one. But here you can find the code for generating the sparql query. We use this to get the instantiation of variables (A, B, ...), we use no query to retrieve all the triples as this could be a lot depending on the rule.

Explorer/api/rdf.js

Lines 343 to 403 in 72b5bc2

	getInstantiations(endpoint, head, tail, rule){
	return new Promise((resolve, reject) => {
	var used_variables = new Set();
	function getEntity(entity){
	if(!variables.includes(entity)){
	return "<" + Code2URI(entity) + ">";
	} else if(entity === "X"){
	return "<" + Code2URI(head) + ">";
	} else if(entity === "Y") {
	return "<" + Code2URI(tail) + ">";
	} else {
	used_variables.add(entity);
	return "?" + entity + "_"
	}
	}
	function getRelation(relation){
	return "<" + Code2URI(relation) + ">";
	}
	var where = "";
	rule.bodies.forEach((element) => {
	where = where + "<<" + getEntity(element.head) + " " + getRelation(element.relation) + " " + getEntity(element.tail) + ">> obl:split obl:train . \n";
	});
	if(used_variables.size == 0){
	console.log(used_variables)
	resolve([]);
	return;
	}
	used_variables.forEach((element) => {
	where = where + "OPTIONAL { ?" + element + "_ <http://www.w3.org/2000/01/rdf-schema#label> " + "?" + element + " . }\n"
	});
	var query = `query=
	PREFIX obl: <${namespace}>
	SELECT ${[...used_variables].map(x => "?" + x).join(" ")} ${[...used_variables].map(x => "?" + x + "_").join(" ")}
	WHERE {
	${where}
	}
	`
	runSPARQL(endpoint, query).then((data) => {
	var res = [];
	for(var i = 0; i < data["results"]["bindings"].length; i++){
	var edge = data["results"]["bindings"][i];
	var instantiation = [];
	used_variables.forEach((element) => {
	var variable = {};
	variable.variable = element;
	variable.label = edge[element]?.value;
	variable.curie = URI2Code(edge[element + "_"]["value"]);
	instantiation.push(variable);
	});
	res.push(instantiation);
	}
	//callback(data["results"]["bindings"])
	resolve(res);
	});
	});
	}

If you mean by "all the triples that correspond to a rule" all triples that are entailed by the body of the rule, you could issue the following query:

E.g. speak(X,Y) -> lives(X,A), lang(A,Y)

  PREFIX obl:  <https://ai-strategies.org/kgc/>
  SELECT ?X ?A ?Y ?X_label ?A_label ?Y_label
  WHERE {
      <<?X https://ai-strategies.org/kgc/lives ?A>> obl:split obl:train .
      <<?A https://ai-strategies.org/kgc/lang ?Y>> obl:split obl:train .
      OPTIONAL {?X <http://www.w3.org/2000/01/rdf-schema#label> ?X_label}"
      OPTIONAL {?A <http://www.w3.org/2000/01/rdf-schema#label> ?A_label}"
      OPTIONAL {?Y <http://www.w3.org/2000/01/rdf-schema#label> ?Y_label}"
  }