org.eclipse.persistence.jpa.jpql.parser.AllOrAnyExpression Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction 346465e
There is a newer version: 5.0.0-B07
/*******************************************************************************
 * 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;

import org.eclipse.persistence.jpa.jpql.WordParser;

/**
 * An ALL conditional expression is a predicate that is true if the comparison
 * operation is true for all values in the result of the subquery or the result of the
 * subquery is empty. An ALL conditional expression is false if the result of
 * the comparison is false for at least one row, and is unknown if neither
 * true nor false.
 * 
 * An ANY conditional expression is a predicate that is true if the comparison
 * operation is true for some value in the result of the subquery. An ANY
 * conditional expression is false if the result of the subquery is empty or if the
 * comparison operation is false for every value in the result of the subquery, and is
 * unknown if neither true nor false. The keyword SOME is
 * synonymous with ANY. The comparison operators used with ALL or ANY
 * conditional expressions are =, <, <=, >, >=, <>. The result of the subquery must be like that of
 * the other argument to the comparison operator in type.
 * 

 * BNF: all_or_any_expression ::= {ALL|ANY|SOME}(subquery)
 *
 * @version 2.4
 * @since 2.3
 * @author Pascal Filion
 */
public final class AllOrAnyExpression extends AbstractSingleEncapsulatedExpression {

	/**
	 * Creates a new AllOrAnyExpression.
	 *
	 * @param parent The parent of this expression
	 */
	public AllOrAnyExpression(AbstractExpression parent) {
		super(parent);
	}

	/**
	 * {@inheritDoc}
	 */
	public void accept(ExpressionVisitor visitor) {
		visitor.visit(this);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public String encapsulatedExpressionBNF() {
		return SubqueryBNF.ID;
	}

	/**
	 * {@inheritDoc}
	 */
	public JPQLQueryBNF getQueryBNF() {
		return getQueryBNF(AllOrAnyExpressionBNF.ID);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected AbstractExpression parse(WordParser wordParser, String queryBNFId, boolean tolerant) {

		if (tolerant) {
			return super.parse(wordParser, queryBNFId, tolerant);
		}

		SimpleSelectStatement expression = new SimpleSelectStatement(this);
		expression.parse(wordParser, tolerant);
		return expression;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected String parseIdentifier(WordParser wordParser) {

		switch (wordParser.character()) {
			case 's': case 'S': {
				return SOME;
			}

			default: {
				switch (wordParser.character(wordParser.position() + 1)) {
					case 'l': case 'L': {
						return ALL;
					}
					default: {
						return ANY;
					}
				}
			}
		}
	}
}