/*
 * Copyright (c) 2008, 2009, 2011 Oracle, Inc. 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.
 */
package javax.persistence;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

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

Used to map the SELECT clause of a SQL query to an entity result. If this annotation is used, the SQL
statement should select all of the columns that are mapped to the entity object. This should include
foreign key columns to related entities. The results obtained when insufficient data is available are
undefined.

  Example:
  Query q = em.createNativeQuery(
      "SELECT o.id, o.quantity, o.item, i.id, i.name, i.description "+
          "FROM Order o, Item i " +
          "WHERE (o.quantity > 25) AND (o.item = i.id)",
      "OrderItemResults");
  @SqlResultSetMapping(name="OrderItemResults",
      entities={
          @EntityResult(entityClass=com.acme.Order.class),
          @EntityResult(entityClass=com.acme.Item.class)
  })

See Also:
SqlResultSetMapping
Since:
Java Persistence 1.0/**
 * Used to map the SELECT clause of a SQL query to an entity result. If this annotation is used, the SQL
 * statement should select all of the columns that are mapped to the entity object. This should include
 * foreign key columns to related entities. The results obtained when insufficient data is available are
 * undefined.
 * <p>
 * <pre>
 *   Example:
 *
 *   Query q = em.createNativeQuery(
 *       "SELECT o.id, o.quantity, o.item, i.id, i.name, i.description "+
 *           "FROM Order o, Item i " +
 *           "WHERE (o.quantity &gt; 25) AND (o.item = i.id)",
 *       "OrderItemResults");
 *   &#064;SqlResultSetMapping(name="OrderItemResults",
 *       entities={
 *           &#064;EntityResult(entityClass=com.acme.Order.class),
 *           &#064;EntityResult(entityClass=com.acme.Item.class)
 *   })
 * </pre>
 *
 * @see SqlResultSetMapping
 * @since Java Persistence 1.0
 */
@Target({})
@Retention(RUNTIME)
public @interface EntityResult {

  
The class of the result.
Returns:
entity class/**
   * The class of the result.
   *
   * @return entity class
   */
  Class entityClass();

  
Maps the columns specified in the SELECT list of the query to the properties or fields of the entity
class.
Returns:
fields/**
   * Maps the columns specified in the SELECT list of the query to the properties or fields of the entity
   * class.
   *
   * @return fields
   */
  FieldResult[] fields() default {};

  
Specifies the column name (or alias) of the column in the SELECT list that is used to determine the
type of the entity instance.
Returns:
disc col/**
   * Specifies the column name (or alias) of the column in the SELECT list that is used to determine the
   * type of the entity instance.
   *
   * @return disc col
   */
  String discriminatorColumn() default "";
}