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/*******************************************************************************
* Copyright (c) 2012, 2014 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;
import org.eclipse.persistence.jpa.jpql.WordParser;
/**
* Returns an expression that allows a join ON clause to be defined.
*
* New to EclipseLink 2.4 and JPA 2.1.
*
*
BNF: join_condition ::= ON conditional_expression
*
* Example: SELECT e FROM Employee e LEFT JOIN e.projects p ON p.budget {@literal >} 10000
*
* @version 2.4
* @since 2.4
* @author James Sutherland
*/
public final class OnClause extends AbstractConditionalClause {
/**
* Creates a new OnClause.
*
* @param parent The parent of this expression
*/
public OnClause(AbstractExpression parent) {
super(parent, ON);
}
/**
* {@inheritDoc}
*/
public void accept(ExpressionVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
public JPQLQueryBNF getQueryBNF() {
return getQueryBNF(OnClauseBNF.ID);
}
/**
* {@inheritDoc}
*/
@Override
protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) {
return word.equalsIgnoreCase(LEFT) ||
word.equalsIgnoreCase(OUTER) ||
word.equalsIgnoreCase(FETCH) ||
word.equalsIgnoreCase(INNER) ||
word.equalsIgnoreCase(JOIN) ||
super.isParsingComplete(wordParser, word, expression);
}
}