| /* |
| * Copyright (c) 1998, 2020 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; |
| |
| |
| // TopLink imports |
| import org.eclipse.persistence.expressions.*; |
| |
| /** |
| * INTERNAL |
| * <p><b>Purpose</b>: Used for the EMPTY collection handling |
| * <p><b>Responsibilities</b>:<ul> |
| * <li> Generate the correct expression for an IS EMPTY in EJBQL |
| * </ul> |
| * @author Jon Driscoll and Joel Lucuik |
| * @since August 2003 |
| */ |
| public class EmptyCollectionComparisonNode extends SimpleConditionalExpressionNode { |
| public boolean notIndicated = false; |
| |
| /** |
| * EmptyCollectionComparisonNode constructor comment. |
| */ |
| public EmptyCollectionComparisonNode() { |
| super(); |
| } |
| |
| /** |
| * INTERNAL |
| * Validate node and calculate its type. |
| */ |
| @Override |
| public void validate(ParseTreeContext context) { |
| if (left != null) { |
| left.validate(context); |
| } |
| TypeHelper typeHelper = context.getTypeHelper(); |
| setType(typeHelper.getBooleanType()); |
| } |
| |
| /** |
| * INTERNAL |
| * Return a EclipseLink expression for this node. |
| */ |
| @Override |
| public Expression generateExpression(GenerationContext context) { |
| //get the variable name from the DotNode's right attribute |
| //...WHERE emp.firstName IS EMPTY |
| String emptyAttributeName = ((AttributeNode)getLeft().getRight()).getAttributeName(); |
| Expression whereClause = getLeft().getLeft().generateExpression(context); |
| if (notIndicated) { |
| return whereClause.notEmpty(emptyAttributeName); |
| } else { |
| return whereClause.isEmpty(emptyAttributeName); |
| } |
| } |
| |
| /** |
| * INTERNAL |
| * Indicate if a NOT was found in the WHERE clause. |
| * Examples: |
| * ...WHERE emp.phoneNumbers IS NOT EMPTY |
| */ |
| public void indicateNot() { |
| notIndicated = true; |
| } |
| |
| } |