Java Code Examples for org.eclipse.rdf4j.query.algebra.QueryRoot#getArg()

@Test
public void testNestedJoins() throws Exception {
    StatementPattern isUndergrad = new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD));
    StatementPattern isProfessor = new StatementPattern(new Var("y"), constant(RDF.TYPE), constant(PROFESSOR));
    StatementPattern takesCourse = new StatementPattern(new Var("x"), constant(TAKES), new Var("c"));
    StatementPattern teachesCourse = new StatementPattern(new Var("y"), constant(TEACHES), new Var("c"));
    QueryRoot queryTree = new QueryRoot(new Join(
            isProfessor,
            new Join(
                    new Join(isUndergrad, takesCourse),
                    teachesCourse)));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    Assert.assertEquals(Sets.newHashSet("x", "y", "c"), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testComplexJoin() throws Exception {
    StatementPattern isUndergrad = new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD));
    StatementPattern isProfessor = new StatementPattern(new Var("y"), constant(RDF.TYPE), constant(PROFESSOR));
    StatementPattern takesCourse = new StatementPattern(new Var("x"), constant(TAKES), new Var("c"));
    StatementPattern teachesCourse = new StatementPattern(new Var("y"), constant(TEACHES), new Var("c"));
    QueryRoot queryTree = new QueryRoot(new Join(
            new Join(isUndergrad, takesCourse),
            new Join(isProfessor, teachesCourse)));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof Join);
    Join topJoin = (Join) queryTree.getArg();
    Assert.assertTrue(topJoin.getLeftArg() instanceof AggregationPipelineQueryNode);
    Assert.assertTrue(topJoin.getRightArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode leftPipeline = (AggregationPipelineQueryNode) topJoin.getLeftArg();
    AggregationPipelineQueryNode rightPipeline = (AggregationPipelineQueryNode) topJoin.getRightArg();
    Assert.assertEquals(Sets.newHashSet("x", "c"), leftPipeline.getAssuredBindingNames());
    Assert.assertEquals(Sets.newHashSet("y", "c"), rightPipeline.getAssuredBindingNames());
}
 

@Test
public void testProjection() throws Exception {
    StatementPattern isUndergrad = new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD));
    StatementPattern isCourse = new StatementPattern(new Var("course"), constant(RDF.TYPE), constant(COURSE));
    StatementPattern hasEdge = new StatementPattern(new Var("x"), new Var("p"), new Var("course"));
    ProjectionElemList projectionElements = new ProjectionElemList(
            new ProjectionElem("p", "relation"),
            new ProjectionElem("course"));
    QueryRoot queryTree = new QueryRoot(new Projection(
            new Join(new Join(isCourse, hasEdge), isUndergrad),
            projectionElements));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    Assert.assertEquals(Sets.newHashSet("relation", "course"), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testMultiProjection() throws Exception {
    StatementPattern isUndergrad = new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD));
    StatementPattern isCourse = new StatementPattern(new Var("course"), constant(RDF.TYPE), constant(COURSE));
    StatementPattern hasEdge = new StatementPattern(new Var("x"), new Var("p"), new Var("course"));
    ProjectionElemList courseHasRelation = new ProjectionElemList(
            new ProjectionElem("p", "relation"),
            new ProjectionElem("course"));
    ProjectionElemList studentHasRelation = new ProjectionElemList(
            new ProjectionElem("p", "relation"),
            new ProjectionElem("x", "student"));
    QueryRoot queryTree = new QueryRoot(new MultiProjection(
            new Join(new Join(isCourse, hasEdge), isUndergrad),
            Arrays.asList(courseHasRelation, studentHasRelation)));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    Assert.assertEquals(Sets.newHashSet("relation"), pipelineNode.getAssuredBindingNames());
    Assert.assertEquals(Sets.newHashSet("relation", "course", "student"), pipelineNode.getBindingNames());
}
 

private void testPipelineQuery(final String query, final Multiset<BindingSet> expectedSolutions) throws Exception {
    // Prepare query and convert to pipeline
    final QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
    final SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
    queryTree.visit(visitor);
    // Execute pipeline and verify results
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    final AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    final Multiset<BindingSet> solutions = HashMultiset.create();
    final CloseableIteration<BindingSet, QueryEvaluationException> iter = pipelineNode.evaluate(new QueryBindingSet());
    while (iter.hasNext()) {
        solutions.add(iter.next());
    }
    Assert.assertEquals(expectedSolutions, solutions);
}
 

@Test
public void testNoVariableSP() throws Exception {
    // Insert data
    insert(OWL.THING, RDF.TYPE, OWL.CLASS);
    insert(FOAF.PERSON, RDF.TYPE, OWL.CLASS, 1);
    insert(FOAF.PERSON, RDFS.SUBCLASSOF, OWL.THING);
    insert(VF.createIRI("urn:Alice"), RDF.TYPE, FOAF.PERSON);
    dao.flush();
    // Define query and expected results
    final String query = "SELECT * WHERE {\n"
            + "  owl:Thing a owl:Class .\n"
            + "}";
    final Multiset<BindingSet> expectedSolutions = HashMultiset.create();
    expectedSolutions.add(new EmptyBindingSet());
    // Execute pipeline and verify results
    final QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
    final SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof Projection);
    final Projection projection = (Projection) queryTree.getArg();
    Assert.assertTrue(projection.getArg() instanceof AggregationPipelineQueryNode);
    final AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) projection.getArg();
    final Multiset<BindingSet> solutions = HashMultiset.create();
    final CloseableIteration<BindingSet, QueryEvaluationException> iter = pipelineNode.evaluate(new QueryBindingSet());
    while (iter.hasNext()) {
        solutions.add(iter.next());
    }
    Assert.assertEquals(expectedSolutions, solutions);
}
 

@Test
public void testTriplePipeline() throws Exception {
    final IRI alice = VF.createIRI("urn:Alice");
    final IRI bob = VF.createIRI("urn:Bob");
    final IRI eve = VF.createIRI("urn:Eve");
    final IRI friend = VF.createIRI("urn:friend");
    final IRI knows = VF.createIRI("urn:knows");
    final IRI year = VF.createIRI("urn:year");
    final Literal yearLiteral = VF.createLiteral("2017", XMLSchema.GYEAR);
    final String query = "CONSTRUCT {\n"
            + "    ?x <urn:knows> ?y .\n"
            + "    ?x <urn:year> \"2017\"^^<" + XMLSchema.GYEAR + "> .\n"
            + "} WHERE { ?x <urn:friend> ?y }";
    insert(alice, friend, bob);
    insert(bob, knows, eve);
    insert(eve, knows, alice);
    // Prepare query and convert to pipeline
    final QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
    final SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
    queryTree.visit(visitor);
    // Get pipeline, add triple conversion, and verify that the result is a
    // properly serialized statement
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    final AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    final List<Bson> triplePipeline = pipelineNode.getTriplePipeline(System.currentTimeMillis(), false);
    final SimpleMongoDBStorageStrategy strategy = new SimpleMongoDBStorageStrategy();
    final List<Statement> results = new LinkedList<>();
    for (final Document doc : getRyaCollection().aggregate(triplePipeline)) {
        final RyaStatement rstmt = strategy.deserializeDocument(doc);
        final Statement stmt = RyaToRdfConversions.convertStatement(rstmt);
        results.add(stmt);
    }
    Assert.assertEquals(2, results.size());
    Assert.assertTrue(results.contains(VF.createStatement(alice, knows, bob)));
    Assert.assertTrue(results.contains(VF.createStatement(alice, year, yearLiteral)));
}
 

@Test
public void testStatementPattern() throws Exception {
    QueryRoot query = new QueryRoot(new StatementPattern(
            new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD)));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    query.visit(visitor);
    Assert.assertTrue(query.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) query.getArg();
    Assert.assertEquals(Sets.newHashSet("x"), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testJoin() throws Exception {
    QueryRoot query = new QueryRoot(new Join(
            new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD)),
            new StatementPattern(new Var("x"), constant(TAKES), new Var("course"))));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    query.visit(visitor);
    Assert.assertTrue(query.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) query.getArg();
    Assert.assertEquals(Sets.newHashSet("x", "course"), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testEmptyProjection() throws Exception {
    StatementPattern isClass = new StatementPattern(constant(UNDERGRAD), constant(RDF.TYPE), constant(OWL.CLASS));
    QueryRoot queryTree = new QueryRoot(new Projection(isClass, new ProjectionElemList()));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof Projection);
    Projection projectNode = (Projection) queryTree.getArg();
    Assert.assertTrue(projectNode.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) projectNode.getArg();
    Assert.assertEquals(Sets.newHashSet(), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testExtension() throws Exception {
    QueryRoot queryTree = new QueryRoot(new Extension(
            new StatementPattern(new Var("x"), constant(TAKES), new Var("c")),
            new ExtensionElem(new Var("x"), "renamed"),
            new ExtensionElem(new ValueConstant(TAKES), "constant")));
    SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    Assert.assertEquals(Sets.newHashSet("x", "c", "renamed", "constant"), pipelineNode.getAssuredBindingNames());
}
 

@Test
public void testRequiredDerivationLevel() throws Exception {
    // Insert data
    final IRI person = VF.createIRI("urn:Person");
    final IRI livingThing = VF.createIRI("urn:LivingThing");
    final IRI human = VF.createIRI("urn:Human");
    final IRI programmer = VF.createIRI("urn:Programmer");
    final IRI thing = VF.createIRI("urn:Thing");
    insert(programmer, RDFS.SUBCLASSOF, person);
    insert(person, RDFS.SUBCLASSOF, FOAF.PERSON);
    insert(FOAF.PERSON, RDFS.SUBCLASSOF, person);
    insert(person, OWL.EQUIVALENTCLASS, human);
    insert(person, RDFS.SUBCLASSOF, livingThing);
    insert(livingThing, RDFS.SUBCLASSOF, thing);
    insert(thing, RDFS.SUBCLASSOF, OWL.THING, 1);
    insert(OWL.THING, RDFS.SUBCLASSOF, thing);
    dao.flush();
    // Define query and expected results
    final String query = "SELECT ?A ?B WHERE {\n"
            + "  ?A rdfs:subClassOf ?B .\n"
            + "  ?B rdfs:subClassOf ?A .\n"
            + "}";
    final List<String> varNames = Arrays.asList("A", "B");
    Multiset<BindingSet> expectedSolutions = HashMultiset.create();
    expectedSolutions.add(new ListBindingSet(varNames, person, FOAF.PERSON));
    expectedSolutions.add(new ListBindingSet(varNames, FOAF.PERSON, person));
    expectedSolutions.add(new ListBindingSet(varNames, thing, OWL.THING));
    expectedSolutions.add(new ListBindingSet(varNames, OWL.THING, thing));
    // Prepare query and convert to pipeline
    final QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
    final SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    final AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    // Extend the pipeline by requiring a derivation level of zero (should have no effect)
    pipelineNode.requireSourceDerivationDepth(0);
    Multiset<BindingSet> solutions = HashMultiset.create();
    CloseableIteration<BindingSet, QueryEvaluationException> iter = pipelineNode.evaluate(new QueryBindingSet());
    while (iter.hasNext()) {
        solutions.add(iter.next());
    }
    Assert.assertEquals(expectedSolutions, solutions);
    // Extend the pipeline by requiring a derivation level of one (should produce the thing/thing pair)
    expectedSolutions = HashMultiset.create();
    expectedSolutions.add(new ListBindingSet(varNames, thing, OWL.THING));
    expectedSolutions.add(new ListBindingSet(varNames, OWL.THING, thing));
    pipelineNode.requireSourceDerivationDepth(1);
    solutions = HashMultiset.create();
    iter = pipelineNode.evaluate(new QueryBindingSet());
    while (iter.hasNext()) {
        solutions.add(iter.next());
    }
    Assert.assertEquals(expectedSolutions, solutions);
}
 

@Test
public void testRequiredTimestamp() throws Exception {
    // Insert data
    final IRI person = VF.createIRI("urn:Person");
    final IRI livingThing = VF.createIRI("urn:LivingThing");
    final IRI human = VF.createIRI("urn:Human");
    final IRI programmer = VF.createIRI("urn:Programmer");
    final IRI thing = VF.createIRI("urn:Thing");
    insert(programmer, RDFS.SUBCLASSOF, person);
    insert(person, RDFS.SUBCLASSOF, FOAF.PERSON, 2);
    insert(FOAF.PERSON, RDFS.SUBCLASSOF, person);
    insert(person, OWL.EQUIVALENTCLASS, human);
    insert(person, RDFS.SUBCLASSOF, livingThing);
    insert(livingThing, RDFS.SUBCLASSOF, thing);
    insert(thing, RDFS.SUBCLASSOF, OWL.THING);
    insert(OWL.THING, RDFS.SUBCLASSOF, thing);
    dao.flush();
    // Define query and expected results
    final String query = "SELECT ?A ?B WHERE {\n"
            + "  ?A rdfs:subClassOf ?B .\n"
            + "  ?B rdfs:subClassOf ?A .\n"
            + "}";
    final List<String> varNames = Arrays.asList("A", "B");
    final Multiset<BindingSet> expectedSolutions = HashMultiset.create();
    expectedSolutions.add(new ListBindingSet(varNames, person, FOAF.PERSON));
    expectedSolutions.add(new ListBindingSet(varNames, FOAF.PERSON, person));
    expectedSolutions.add(new ListBindingSet(varNames, thing, OWL.THING));
    expectedSolutions.add(new ListBindingSet(varNames, OWL.THING, thing));
    // Prepare query and convert to pipeline
    final QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
    final SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
    queryTree.visit(visitor);
    Assert.assertTrue(queryTree.getArg() instanceof AggregationPipelineQueryNode);
    final AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) queryTree.getArg();
    // Extend the pipeline by requiring a timestamp of zero (should have no effect)
    pipelineNode.requireSourceTimestamp(0);
    final Multiset<BindingSet> solutions = HashMultiset.create();
    CloseableIteration<BindingSet, QueryEvaluationException> iter = pipelineNode.evaluate(new QueryBindingSet());
    while (iter.hasNext()) {
        solutions.add(iter.next());
    }
    Assert.assertEquals(expectedSolutions, solutions);
    // Extend the pipeline by requiring a future timestamp (should produce no results)
    final long delta = 1000 * 60 * 60 * 24;
    pipelineNode.requireSourceTimestamp(System.currentTimeMillis() + delta);
    iter = pipelineNode.evaluate(new QueryBindingSet());
    Assert.assertFalse(iter.hasNext());
}