org.eclipse.persistence.internal.jpa.parsing.SubqueryNode Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction f2b9fc5
There is a newer version: 5.0.0-B03
/*
 * Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.jpa.parsing;

import java.util.Set;

import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.queries.ReportQuery;

/**
 * INTERNAL
 * Purpose: Represent a subquery.
 */
public class SubqueryNode extends Node {

    private JPQLParseTree subqueryParseTree;

    /** Set of names of variables declared in an outer scope and used in teh
     * subquery. */
    private Set outerVars;

    /**
     * Return a new SubqueryNode.
     */
    public SubqueryNode() {
        super();
    }

    /** */
    public ReportQuery getReportQuery(GenerationContext context) {
        ReportQuery innerQuery = new ReportQuery();
        GenerationContext innerContext =
            subqueryParseTree.populateSubquery(innerQuery, context);
        Expression joins = innerContext.joinVariables(outerVars);
        if (joins != null) {
            Expression where = innerQuery.getSelectionCriteria();
            where = appendExpression(where, joins);
            innerQuery.setSelectionCriteria(where);
        }
        return innerQuery;
    }

    /**
     * INTERNAL
     * If called the subquery is part of the WHERE clause of an UPDATE or
     * DELETE statement that does not define an identification variable.
     * The method checks the clauses of the subquery for unqualified fields
     * accesses.
     */
    public Node qualifyAttributeAccess(ParseTreeContext context) {
        subqueryParseTree.getFromNode().qualifyAttributeAccess(context);
        subqueryParseTree.getQueryNode().qualifyAttributeAccess(context);
        if (subqueryParseTree.getWhereNode() != null) {
            subqueryParseTree.getWhereNode().qualifyAttributeAccess(context);
        }
        if (subqueryParseTree.getGroupByNode() != null) {
            subqueryParseTree.getGroupByNode().qualifyAttributeAccess(context);
        }
        if (subqueryParseTree.getHavingNode() != null) {
            subqueryParseTree.getHavingNode().qualifyAttributeAccess(context);
        }
        return this;
    }

    /**
     * INTERNAL
     * Validate node and calculate its type.
     */
    public void validate(ParseTreeContext context) {
        subqueryParseTree.validate(context);
        outerVars = context.getOuterScopeVariables();
        SelectNode selectNode = (SelectNode)subqueryParseTree.getQueryNode();
        // Get the select expression, subqueries only have one
        Node selectExpr = (Node)selectNode.getSelectExpressions().get(0);
        setType(selectExpr.getType());
    }

    /**
     * INTERNAL
     * Generate the EclipseLink expression for this node
     */
    public Expression generateExpression(GenerationContext context) {
        Expression base = context.getBaseExpression();
        ReportQuery innerQuery = getReportQuery(context);
        return base.subQuery(innerQuery);
    }

    /**
     * INTERNAL
     * Is this node a SubqueryNode
     */
    public boolean isSubqueryNode() {
        return true;
    }

    /** */
    public void setParseTree(JPQLParseTree parseTree) {
        this.subqueryParseTree = parseTree;
    }

    /** */
    public JPQLParseTree getParseTree() {
        return subqueryParseTree;
    }

}