org.eclipse.persistence.jpa.jpql.parser.LocateExpression Maven / Gradle / Ivy
Show all versions of eclipselink Show documentation
/*
* Copyright (c) 2006, 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
//
package org.eclipse.persistence.jpa.jpql.parser;
/**
* The LOCATE function returns the position of a given string within a string, starting the
* search at a specified position. It returns the first position at which the string was found as an
* integer. The first argument is the string to be located; the second argument is the string to be
* searched; the optional third argument is an integer that represents the string position at which
* the search is started (by default, the beginning of the string to be searched). The first
* position in a string is denoted by 1. If the string is not found, 0 is returned. The LOCATE
* function returns the length of the string in characters as an integer.
*
* JPA 1.0, 2.0:
*
BNF: expression ::= LOCATE(string_primary, string_primary [, simple_arithmetic_expression])
*
* JPA 2.1:
*
BNF: expression ::= LOCATE(string_expression, string_expression [, arithmetic_expression])
*
*
* @version 2.5
* @since 2.3
* @author Pascal Filion
*/
public final class LocateExpression extends AbstractTripleEncapsulatedExpression {
/**
* Creates a new LocateExpression.
*
* @param parent The parent of this expression
*/
public LocateExpression(AbstractExpression parent) {
super(parent, LOCATE);
}
@Override
public void accept(ExpressionVisitor visitor) {
visitor.visit(this);
}
@Override
public String getParameterQueryBNFId(int index) {
switch (index) {
case 2: return InternalLocateThirdExpressionBNF.ID;
default: return InternalLocateStringExpressionBNF.ID;
}
}
@Override
public JPQLQueryBNF getQueryBNF() {
return getQueryBNF(FunctionsReturningNumericsBNF.ID);
}
@Override
protected boolean isThirdExpressionOptional() {
return true;
}
}