Examples with ConjunctiveQuery fr.lirmm.graphik.graal.api.core.ConjunctiveQuery used on opensource projects

Example 31 with ConjunctiveQuery

use of fr.lirmm.graphik.graal.api.core.ConjunctiveQuery in project graal by graphik-team.

the class RdbmsAtomIterator method hasNext.

// /////////////////////////////////////////////////////////////////////////
// METHODS
// /////////////////////////////////////////////////////////////////////////
@Override
public boolean hasNext() throws IteratorException {
    if (!this.hasNextCallDone) {
        this.hasNextCallDone = true;
        while (this.predicateIt.hasNext() && (this.atomIt == null || !this.atomIt.hasNext())) {
            Predicate p = predicateIt.next();
            List<Term> terms = new LinkedList<Term>();
            VariableGenerator gen = new DefaultVariableGenerator("X");
            for (int i = 0; i < p.getArity(); ++i) {
                terms.add(gen.getFreshSymbol());
            }
            InMemoryAtomSet atomSet = new LinkedListAtomSet();
            Atom atom = new DefaultAtom(p, terms);
            atomSet.add(atom);
            ConjunctiveQuery query = DefaultConjunctiveQueryFactory.instance().create(atomSet);
            SqlHomomorphism solver = SqlHomomorphism.instance();
            try {
                this.atomIt = new SubstitutionIterator2AtomIterator(atom, solver.execute(query, this.store));
            } catch (HomomorphismException e) {
                throw new IteratorException(e);
            }
        }
    }
    return this.atomIt != null && this.atomIt.hasNext();
}

Example 32 with ConjunctiveQuery

use of fr.lirmm.graphik.graal.api.core.ConjunctiveQuery in project graal by graphik-team.

the class SqlUCQHomomorphism method preprocessing.

private static SQLQuery preprocessing(UnionOfConjunctiveQueries queries, RdbmsStore store) throws HomomorphismException {
    boolean emptyQuery = false;
    CloseableIterator<ConjunctiveQuery> it = queries.iterator();
    StringBuilder ucq = new StringBuilder();
    RdbmsConjunctiveQueryTranslator translator = store.getConjunctiveQueryTranslator();
    try {
        if (!it.hasNext())
            return SQLQuery.hasSchemaErrorInstance();
        while (it.hasNext()) {
            SQLQuery query = translator.translate(it.next());
            if (!query.hasSchemaError()) {
                if (ucq.length() > 0)
                    ucq.append("\nUNION\n");
                ucq.append(query.toString());
            } else if (query.isEmpty()) {
                emptyQuery = true;
            }
        }
    } catch (Exception e) {
        throw new HomomorphismException("Error during query translation to SQL", e);
    }
    SQLQuery query = new SQLQuery(ucq.toString());
    if (query.isEmpty() && !emptyQuery) {
        return SQLQuery.hasSchemaErrorInstance();
    }
    return query;
}

Example 33 with ConjunctiveQuery

use of fr.lirmm.graphik.graal.api.core.ConjunctiveQuery in project graal by graphik-team.

the class RDF4jStore method match.

@Override
public CloseableIterator<Atom> match(Atom atom) throws AtomSetException {
    ConjunctiveQuery query = DefaultConjunctiveQueryFactory.instance().create(atom);
    StringWriter s = new StringWriter();
    SparqlConjunctiveQueryWriter w = new SparqlConjunctiveQueryWriter(s, this.utils.getURIzer());
    try {
        w.write(query);
        w.close();
    } catch (IOException e1) {
        throw new AtomSetException("Error while converting to SPARQL " + atom, e1);
    }
    TupleQuery sparqlQuery = this.connection.prepareTupleQuery(s.toString());
    TupleQueryResult result = sparqlQuery.evaluate();
    return new TupleQueryResultAtomIterator(result, atom, utils);
}

Example 34 with ConjunctiveQuery

use of fr.lirmm.graphik.graal.api.core.ConjunctiveQuery in project graal by graphik-team.

the class ConjunctiveQuery2Test method nonexistingPredicateQuery.

@Theory
public void nonexistingPredicateQuery(Homomorphism<ConjunctiveQuery, AtomSet> h, AtomSet store) {
    try {
        store.addAll(DlgpParser.parseAtomSet("<P>(a,b)."));
        ConjunctiveQuery query = DlgpParser.parseQuery("?(X,Y) :- q(X,Y).");
        CloseableIterator<Substitution> subReader;
        subReader = h.execute(query, store);
        Assert.assertFalse(subReader.hasNext());
        subReader.close();
    } catch (Exception e) {
        Assert.assertTrue(e.getMessage(), false);
    }
}

Example 35 with ConjunctiveQuery

use of fr.lirmm.graphik.graal.api.core.ConjunctiveQuery in project graal by graphik-team.

the class ConjunctiveQuery2Test method wrongArityQuery2.

@Theory
public void wrongArityQuery2(Homomorphism<ConjunctiveQuery, AtomSet> h, AtomSet store) {
    Assume.assumeFalse(store instanceof TripleStore);
    try {
        store.add(DlgpParser.parseAtom("<P>(a,b)."));
        ConjunctiveQuery query = DlgpParser.parseQuery("? :- <P>(X,Y,Z).");
        CloseableIterator<Substitution> subReader;
        subReader = h.execute(query, store);
        Assert.assertFalse(subReader.hasNext());
        subReader.close();
    } catch (Exception e) {
        Assert.assertTrue(e.getMessage(), false);
    }
}