Java tutorial
/******************************************************************************* * Copyright (c) 2008 - 2013 Oracle Corporation. 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: * Linda DeMichiel - Java Persistence 2.1 * Linda DeMichiel - Java Persistence 2.0 * ******************************************************************************/ package javax.persistence.criteria; import javax.persistence.TupleElement; import java.util.List; /** * The <code>Selection</code> interface defines an item that is to be * returned in a query result. * * @param <X> the type of the selection item * * @since Java Persistence 2.0 */ public interface Selection<X> extends TupleElement<X> { /** * Assigns an alias to the selection item. * Once assigned, an alias cannot be changed or reassigned. * Returns the same selection item. * @param name alias * @return selection item */ Selection<X> alias(String name); /** * Whether the selection item is a compound selection. * @return boolean indicating whether the selection is a compound * selection */ boolean isCompoundSelection(); /** * Return the selection items composing a compound selection. * Modifications to the list do not affect the query. * @return list of selection items * @throws IllegalStateException if selection is not a * compound selection */ List<Selection<?>> getCompoundSelectionItems(); }