Examples with Order org.eclipse.rdf4j.query.algebra.Order used on opensource projects

Example 1 with Order

use of org.eclipse.rdf4j.query.algebra.Order in project rdf4j by eclipse.

the class QueryModelBuilder method visit.

@Override
public TupleExpr visit(ASTSelectQuery node, Object data) throws VisitorException {
    TupleExpr tupleExpr;
    ASTQueryBody queryBodyNode = node.getQueryBody();
    if (queryBodyNode != null) {
        // Build tuple expression for query body
        tupleExpr = (TupleExpr) queryBodyNode.jjtAccept(this, null);
    } else {
        tupleExpr = new SingletonSet();
    }
    // Apply result ordering
    ASTOrderBy orderByNode = node.getOrderBy();
    if (orderByNode != null) {
        List<OrderElem> orderElemements = (List<OrderElem>) orderByNode.jjtAccept(this, null);
        tupleExpr = new Order(tupleExpr, orderElemements);
    }
    // Apply projection
    tupleExpr = (TupleExpr) node.getSelectClause().jjtAccept(this, tupleExpr);
    // process limit and offset clauses, if present.
    ASTLimit limitNode = node.getLimit();
    int limit = -1;
    if (limitNode != null) {
        limit = (Integer) limitNode.jjtAccept(this, null);
    }
    ASTOffset offsetNode = node.getOffset();
    int offset = -1;
    if (offsetNode != null) {
        offset = (Integer) offsetNode.jjtAccept(this, null);
    }
    if (offset >= 1 || limit >= 0) {
        tupleExpr = new Slice(tupleExpr, offset, limit);
    }
    return tupleExpr;
}

Example 2 with Order

use of org.eclipse.rdf4j.query.algebra.Order in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public TupleExpr visit(ASTSelect node, Object data) throws VisitorException {
    TupleExpr result = (TupleExpr) data;
    final Order orderClause = result instanceof Order ? (Order) result : null;
    Extension extension = new Extension();
    ProjectionElemList projElemList = new ProjectionElemList();
    GroupFinder groupFinder = new GroupFinder();
    result.visit(groupFinder);
    Group group = groupFinder.getGroup();
    boolean existingGroup = group != null;
    List<String> aliasesInProjection = new ArrayList<String>();
    for (ASTProjectionElem projElemNode : node.getProjectionElemList()) {
        Node child = projElemNode.jjtGetChild(0);
        String alias = projElemNode.getAlias();
        if (alias != null) {
            // aliased projection element
            if (aliasesInProjection.contains(alias)) {
                throw new VisitorException("duplicate use of alias '" + alias + "' in projection.");
            }
            // check if alias is not previously used.
            if (result.getBindingNames().contains(alias)) {
                throw new VisitorException("projection alias '" + alias + "' was previously used");
            }
            aliasesInProjection.add(alias);
            ValueExpr valueExpr = (ValueExpr) child.jjtAccept(this, null);
            String targetName = alias;
            String sourceName = alias;
            if (child instanceof ASTVar) {
                sourceName = ((ASTVar) child).getName();
            }
            ProjectionElem elem = new ProjectionElem(sourceName, targetName);
            projElemList.addElement(elem);
            AggregateCollector collector = new AggregateCollector();
            valueExpr.visit(collector);
            if (collector.getOperators().size() > 0) {
                elem.setAggregateOperatorInExpression(true);
                for (AggregateOperator operator : collector.getOperators()) {
                    // Apply implicit grouping if necessary
                    if (group == null) {
                        group = new Group(result);
                    }
                    if (operator.equals(valueExpr)) {
                        group.addGroupElement(new GroupElem(alias, operator));
                        extension.setArg(group);
                    } else {
                        ValueExpr expr = (ValueExpr) operator.getParentNode();
                        Extension anonymousExtension = new Extension();
                        Var anonVar = createAnonVar();
                        expr.replaceChildNode(operator, anonVar);
                        anonymousExtension.addElement(new ExtensionElem(operator, anonVar.getName()));
                        anonymousExtension.setArg(result);
                        result = anonymousExtension;
                        group.addGroupElement(new GroupElem(anonVar.getName(), operator));
                    }
                    if (!existingGroup) {
                        result = group;
                    }
                }
            }
            // add extension element reference to the projection element and
            // to
            // the extension
            ExtensionElem extElem = new ExtensionElem(valueExpr, alias);
            extension.addElement(extElem);
            elem.setSourceExpression(extElem);
        } else if (child instanceof ASTVar) {
            Var projVar = (Var) child.jjtAccept(this, null);
            ProjectionElem elem = new ProjectionElem(projVar.getName());
            projElemList.addElement(elem);
            VarCollector whereClauseVarCollector = new VarCollector();
            result.visit(whereClauseVarCollector);
            if (!whereClauseVarCollector.collectedVars.contains(projVar)) {
                ExtensionElem extElem = new ExtensionElem(projVar, projVar.getName());
                extension.addElement(extElem);
                elem.setSourceExpression(extElem);
            }
        } else {
            throw new IllegalStateException("required alias for non-Var projection elements not found");
        }
    }
    if (!extension.getElements().isEmpty()) {
        if (orderClause != null) {
            // Extensions produced by SELECT expressions should be nested
            // inside
            // the ORDER BY clause, to make sure
            // sorting can work on the newly introduced variable. See
            // SES-892
            // and SES-1809.
            TupleExpr arg = orderClause.getArg();
            extension.setArg(arg);
            orderClause.setArg(extension);
            result = orderClause;
        } else {
            extension.setArg(result);
            result = extension;
        }
    }
    result = new Projection(result, projElemList);
    if (group != null) {
        for (ProjectionElem elem : projElemList.getElements()) {
            if (!elem.hasAggregateOperatorInExpression()) {
                Set<String> groupNames = group.getBindingNames();
                ExtensionElem extElem = elem.getSourceExpression();
                if (extElem != null) {
                    ValueExpr expr = extElem.getExpr();
                    VarCollector collector = new VarCollector();
                    expr.visit(collector);
                    for (Var var : collector.getCollectedVars()) {
                        if (!groupNames.contains(var.getName())) {
                            throw new VisitorException("variable '" + var.getName() + "' in projection not present in GROUP BY.");
                        }
                    }
                } else {
                    if (!groupNames.contains(elem.getTargetName())) {
                        throw new VisitorException("variable '" + elem.getTargetName() + "' in projection not present in GROUP BY.");
                    } else if (!groupNames.contains(elem.getSourceName())) {
                        throw new VisitorException("variable '" + elem.getSourceName() + "' in projection not present in GROUP BY.");
                    }
                }
            }
        }
    }
    if (node.isSubSelect()) {
        // set context var at the level of the projection. This allows us
        // to distinguish named graphs selected in the
        // outer query from named graphs selected as part of the sub-select.
        ((Projection) result).setProjectionContext(graphPattern.getContextVar());
    }
    if (node.isDistinct()) {
        result = new Distinct(result);
    } else if (node.isReduced()) {
        result = new Reduced(result);
    }
    return result;
}

Example 3 with Order

use of org.eclipse.rdf4j.query.algebra.Order in project rdf4j by eclipse.

the class SPARQLParserTest method testOrderByWithAliases1.

@Test
public void testOrderByWithAliases1() throws Exception {
    String queryString = " SELECT ?x (SUM(?v1)/COUNT(?v1) as ?r) WHERE { ?x <urn:foo> ?v1 } GROUP BY ?x ORDER BY ?r";
    ParsedQuery query = parser.parseQuery(queryString, null);
    assertNotNull(query);
    TupleExpr te = query.getTupleExpr();
    assertTrue(te instanceof Projection);
    te = ((Projection) te).getArg();
    assertTrue(te instanceof Order);
    te = ((Order) te).getArg();
    assertTrue(te instanceof Extension);
}

Example 4 with Order

use of org.eclipse.rdf4j.query.algebra.Order in project rdf4j by eclipse.

the class TupleExprBuilderTest method testAskQuerySolutionModifiers.

@Test
public void testAskQuerySolutionModifiers() {
    String query = "ASK WHERE { ?foo ?bar ?baz . } ORDER BY ?foo LIMIT 1";
    try {
        TupleExprBuilder builder = new TupleExprBuilder(ValueFactoryImpl.getInstance());
        ASTQueryContainer qc = SyntaxTreeBuilder.parseQuery(query);
        TupleExpr result = builder.visit(qc, null);
        assertTrue(result instanceof Order);
    } catch (Exception e) {
        e.printStackTrace();
        fail("should parse ask query with solution modifiers");
    }
}

Example 5 with Order

use of org.eclipse.rdf4j.query.algebra.Order in project rdf4j by eclipse.

the class QueryModelBuilder method visit.

@Override
public TupleExpr visit(ASTConstructQuery node, Object data) throws VisitorException {
    TupleExpr tupleExpr;
    if (node.hasQueryBody()) {
        // Build tuple expression for query body
        tupleExpr = (TupleExpr) node.getQueryBody().jjtAccept(this, null);
    } else {
        tupleExpr = new SingletonSet();
    }
    // Apply result ordering
    ASTOrderBy orderByNode = node.getOrderBy();
    if (orderByNode != null) {
        List<OrderElem> orderElemements = (List<OrderElem>) orderByNode.jjtAccept(this, null);
        tupleExpr = new Order(tupleExpr, orderElemements);
    }
    // Create constructor
    ConstructorBuilder cb = new ConstructorBuilder();
    ASTConstruct constructNode = node.getConstructClause();
    if (!constructNode.isWildcard()) {
        TupleExpr constructExpr = (TupleExpr) constructNode.jjtAccept(this, null);
        tupleExpr = cb.buildConstructor(tupleExpr, constructExpr, constructNode.isDistinct(), constructNode.isReduced());
    } else if (node.hasQueryBody()) {
        tupleExpr = cb.buildConstructor(tupleExpr, constructNode.isDistinct(), constructNode.isReduced());
    }
    // else: "construct *" without query body, just return the SingletonSet
    // process limit and offset clauses, if present.
    ASTLimit limitNode = node.getLimit();
    int limit = -1;
    if (limitNode != null) {
        limit = (Integer) limitNode.jjtAccept(this, null);
    }
    ASTOffset offsetNode = node.getOffset();
    int offset = -1;
    if (offsetNode != null) {
        offset = (Integer) offsetNode.jjtAccept(this, null);
    }
    if (offset >= 1 || limit >= 0) {
        tupleExpr = new Slice(tupleExpr, offset, limit);
    }
    return tupleExpr;
}