src/javax/persistence/ColumnResult.java

/*******************************************************************************
 * Copyright (c) 1998, 2009 Oracle. 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:
 *     dclarke - Java Persistence 2.0 - Proposed Final Draft (March 13, 2009)
 *     		     Specification available from http://jcp.org/en/jsr/detail?id=317
 *
 * Java(TM) Persistence API, Version 2.0 - EARLY ACCESS
 * This is an implementation of an early-draft specification developed under the 
 * Java Community Process (JCP).  The code is untested and presumed not to be a  
 * compatible implementation of JSR 317: Java(TM) Persistence API, Version 2.0.   
 * We encourage you to migrate to an implementation of the Java(TM) Persistence 
 * API, Version 2.0 Specification that has been tested and verified to be compatible 
 * as soon as such an implementation is available, and we encourage you to retain 
 * this notice in any implementation of Java(TM) Persistence API, Version 2.0 
 * Specification that you distribute.
 ******************************************************************************/
package javax.persistence;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * References name of a column in the SELECT clause of a SQL query - 
 * i.e., column alias, if applicable. Scalar result types can be 
 * included in the query result by specifying this annotation in 
 * the metadata.
 *
 * <pre>
 *
 * Example:
 *   Query q = em.createNativeQuery(
 *       "SELECT o.id AS order_id, " +
 *           "o.quantity AS order_quantity, " +
 *           "o.item AS order_item, " + 
 *           "i.name AS item_name, " +
 *         "FROM Order o, Item i " +
 *         "WHERE (order_quantity > 25) AND (order_item = i.id)",
 *       "OrderResults");
 *
 *   &#064;SqlResultSetMapping(name="OrderResults",
 *       entities={
 *           &#064;EntityResult(entityClass=com.acme.Order.class, fields={
 *               &#064;FieldResult(name="id", column="order_id"),
 *               &#064;FieldResult(name="quantity", column="order_quantity"),
 *               &#064;FieldResult(name="item", column="order_item")})},
 *       columns={
 *           &#064;ColumnResult(name="item_name")}
 *       )
 * </pre>
 *
 * @since Java Persistence 1.0
 */
@Target({}) 
@Retention(RUNTIME)

public @interface ColumnResult { 

    /** The name of a column in the SELECT clause of a SQL query */
    String name();
}