org.eclipse.persistence.jpa.jpql.parser.SumFunction 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;

/**
 * One of the aggregate functions. The arguments must be numeric.
 * 
 * SUM returns Long when applied to state-fields of integral types (other than
 * BigInteger); Double when applied to state-fields of floating point
 * types; BigInteger when applied to state-fields of type BigInteger; and
 * BigDecimal when applied to state-fields of type BigDecimal. If
 * SUM, AVG, MAX, or MIN is used, and there are no values to which the
 * aggregate function can be applied, the result of the aggregate function is NULL. If
 * COUNT is used, and there are no values to which COUNT can be applied, the
 * result of the aggregate function is 0.
 * 

 * BNF: expression ::= SUM([DISTINCT] state_field_path_expression)
 * 
 *
 * @version 2.4
 * @since 2.3
 * @author Pascal Filion
 */
public final class SumFunction extends AggregateFunction {

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

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

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