/******************************************************************************* | |
* Copyright (c) 2006, 2013 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 v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* Oracle - initial API and implementation | |
* | |
******************************************************************************/ | |
package org.eclipse.persistence.jpa.jpql.parser; | |
/** | |
* The <b>LOCATE</b> 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 <b>LOCATE</b> | |
* function returns the length of the string in characters as an integer. | |
* <p> | |
* JPA 1.0, 2.0: | |
* <div nowrap><b>BNF:</b> <code>expression ::= LOCATE(string_primary, string_primary [, simple_arithmetic_expression])</code> | |
* <p> | |
* JPA 2.1: | |
* <div nowrap><b>BNF:</b> <code>expression ::= LOCATE(string_expression, string_expression [, arithmetic_expression])</code> | |
* <p> | |
* | |
* @version 2.5 | |
* @since 2.3 | |
* @author Pascal Filion | |
*/ | |
public final class LocateExpression extends AbstractTripleEncapsulatedExpression { | |
/** | |
* Creates a new <code>LocateExpression</code>. | |
* | |
* @param parent The parent of this expression | |
*/ | |
public LocateExpression(AbstractExpression parent) { | |
super(parent, LOCATE); | |
} | |
/** | |
* {@inheritDoc} | |
*/ | |
public void accept(ExpressionVisitor visitor) { | |
visitor.visit(this); | |
} | |
/** | |
* {@inheritDoc} | |
*/ | |
@Override | |
public String getParameterQueryBNFId(int index) { | |
switch (index) { | |
case 2: return InternalLocateThirdExpressionBNF.ID; | |
default: return InternalLocateStringExpressionBNF.ID; | |
} | |
} | |
/** | |
* {@inheritDoc} | |
*/ | |
public JPQLQueryBNF getQueryBNF() { | |
return getQueryBNF(FunctionsReturningNumericsBNF.ID); | |
} | |
/** | |
* {@inheritDoc} | |
*/ | |
@Override | |
protected boolean isThirdExpressionOptional() { | |
return true; | |
} | |
} |