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

Example 11 with Join

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

the class TupleExprBuilder method visit.

@Override
public TupleExpr visit(ASTAskQuery node, Object data) throws VisitorException {
    graphPattern = new GraphPattern();
    super.visit(node, null);
    TupleExpr tupleExpr = graphPattern.buildTupleExpr();
    tupleExpr = new Slice(tupleExpr, 0, 1);
    // Apply grouping
    Group group = null;
    ASTGroupClause groupNode = node.getGroupClause();
    if (groupNode != null) {
        tupleExpr = (TupleExpr) groupNode.jjtAccept(this, tupleExpr);
        group = (Group) tupleExpr;
    }
    final ASTHavingClause havingClause = node.getHavingClause();
    if (havingClause != null) {
        if (group == null) {
            // create implicit group
            group = new Group(tupleExpr);
        }
        // Apply HAVING group filter condition
        tupleExpr = processHavingClause(havingClause, tupleExpr, group);
    }
    // process bindings clause
    final ASTBindingsClause bindingsClause = node.getBindingsClause();
    if (bindingsClause != null) {
        tupleExpr = new Join((BindingSetAssignment) bindingsClause.jjtAccept(this, null), tupleExpr);
    }
    final ASTOrderClause orderClause = node.getOrderClause();
    if (orderClause != null) {
        if (group == null) {
            // create implicit group
            group = new Group(tupleExpr);
        }
        // Apply result ordering
        tupleExpr = processOrderClause(node.getOrderClause(), tupleExpr, group);
    }
    return tupleExpr;
}

Example 12 with Join

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

the class AbstractQueryBuilder method groupAsJoin.

private TupleExpr groupAsJoin(List<Group> theList) {
    BinaryTupleOperator aJoin = new Join();
    Filter aFilter = null;
    for (Group aGroup : theList) {
        TupleExpr aExpr = aGroup.expr();
        if (aExpr == null) {
            continue;
        }
        if (aExpr instanceof Filter && (((Filter) aExpr).getArg() == null || ((Filter) aExpr).getArg() instanceof EmptySet)) {
            if (aFilter == null) {
                aFilter = (Filter) aExpr;
            } else {
                // if we already have a filter w/ an empty arg, let's And the
                // conditions together.
                aFilter.setCondition(new And(aFilter.getCondition(), ((Filter) aExpr).getCondition()));
            }
            continue;
        }
        if (aFilter != null) {
            aFilter.setArg(aExpr);
            aExpr = aFilter;
            aFilter = null;
        }
        if (aGroup.isOptional()) {
            LeftJoin lj = new LeftJoin();
            TupleExpr aLeft = joinOrExpr(aJoin);
            if (aLeft != null) {
                lj.setLeftArg(aLeft);
                lj.setRightArg(aExpr);
                aJoin = lj;
                continue;
            }
        }
        if (aJoin.getLeftArg() == null) {
            aJoin.setLeftArg(aExpr);
        } else if (aJoin.getRightArg() == null) {
            aJoin.setRightArg(aExpr);
        } else {
            Join aNewJoin = new Join();
            aNewJoin.setLeftArg(aJoin);
            aNewJoin.setRightArg(aExpr);
            aJoin = aNewJoin;
        }
    }
    TupleExpr aExpr = joinOrExpr(aJoin);
    if (aFilter != null) {
        aFilter.setArg(aExpr);
        aExpr = aFilter;
    }
    return aExpr;
}