| /* |
| * 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; |
| |
| /** |
| * The second and third arguments of the <b>SUBSTRING</b> function denote the starting position and |
| * length of the substring to be returned. These arguments are integers. The first position of a |
| * string is denoted by 1. The <b>SUBSTRING</b> function returns a string. |
| * <br> |
| * JPA 1.0: |
| * <div><b>BNF</b> ::= <code>SUBSTRING(string_primary, simple_arithmetic_expression, simple_arithmetic_expression)</code></div> |
| * <br> |
| * JPA 2.0: |
| * <div><b>BNF</b> ::= <code>SUBSTRING(string_primary, simple_arithmetic_expression [, simple_arithmetic_expression])</code></div> |
| * <br> |
| * JPA 2.1: |
| * <div><b>BNF</b> ::= <code>SUBSTRING(string_expression, arithmetic_expression [, arithmetic_expression])</code></div> |
| * |
| * <div>Example: <b>UPDATE</b> Employee e <b>SET</b> e.firstName = <b>SUBSTRING</b>('TopLink Workbench', 1, 8)</div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class SubstringExpression extends AbstractTripleEncapsulatedExpression { |
| |
| /** |
| * Creates a new <code>SubstringExpression</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public SubstringExpression(AbstractExpression parent) { |
| super(parent, SUBSTRING); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public String getParameterQueryBNFId(int index) { |
| switch (index) { |
| case 0: return InternalSubstringStringExpressionBNF.ID; |
| default: return InternalSubstringPositionExpressionBNF.ID; |
| } |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(FunctionsReturningStringsBNF.ID); |
| } |
| |
| @Override |
| protected boolean isThirdExpressionOptional() { |
| return true; |
| } |
| } |