| /* |
| * Copyright (c) 2006, 2021 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 |
| // |
| package org.eclipse.persistence.jpa.jpql.parser; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * The <b>CONCAT</b> function returns a string that is a concatenation of its arguments. |
| * <p> |
| * JPA 1.0: |
| * <div><b>BNF:</b> <code>expression ::= CONCAT(string_primary, string_primary)</code></div> |
| * <br> |
| * JPA 2.0: |
| * <div><b>BNF:</b> <code>expression ::= CONCAT(string_primary, string_primary {, string_primary}*)</code></div> |
| * <br> |
| * JPA 2.1: |
| * <div><b>BNF:</b> <code>expression ::= CONCAT(string_expression, string_expression {, string_expression}*)</code></div> |
| * |
| * <div>Example: <b>SELECT</b> c.firstName <b>FROM</b> Customer c <b>HAVING</b> c.firstName = <b>CONCAT</b>(:fname, :lname)</div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class ConcatExpression extends AbstractSingleEncapsulatedExpression { |
| |
| /** |
| * Creates a new <code>ConcatExpression</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public ConcatExpression(AbstractExpression parent) { |
| super(parent, CONCAT); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| /** |
| * Creates a new {@link CollectionExpression} that will wrap the single constructor item. |
| * |
| * @return The single constructor item represented by a temporary collection |
| */ |
| public CollectionExpression buildCollectionExpression() { |
| |
| List<AbstractExpression> children = new ArrayList<>(1); |
| children.add((AbstractExpression) getExpression()); |
| |
| List<Boolean> commas = new ArrayList<>(1); |
| commas.add(Boolean.FALSE); |
| |
| List<Boolean> spaces = new ArrayList<>(1); |
| spaces.add(Boolean.FALSE); |
| |
| return new CollectionExpression(this, children, commas, spaces, true); |
| } |
| |
| @Override |
| public String getEncapsulatedExpressionQueryBNFId() { |
| return InternalConcatExpressionBNF.ID; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(FunctionsReturningStringsBNF.ID); |
| } |
| } |