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/*
 * Copyright (c) 2008, 2020 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 v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Linda DeMichiel - 2.1
//     Linda DeMichiel - 2.0

package jakarta.persistence;

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

/**
 * Used in conjunction with the {@link SqlResultSetMapping} annotation to map the SELECT
 * clause of a SQL query to a constructor.
 *
 * 

Applies a constructor for the target class, passing in as arguments * values from the specified columns. All columns corresponding * to arguments of the intended constructor must be specified using the * columns element of the ConstructorResult * annotation in the same order as that of the argument list of the * constructor. Any entities returned as constructor results will be * in either the new or detached state, depending on whether a primary * key is retrieved for the constructed object. * *

 *
 * Example:
 *
 *   Query q = em.createNativeQuery(
 *      "SELECT c.id, c.name, COUNT(o) as orderCount, AVG(o.price) AS avgOrder " +
 *      "FROM Customer c, Orders o " +
 *      "WHERE o.cid = c.id " +
 *      "GROUP BY c.id, c.name",
 *      "CustomerDetailsResult");
 *
 *   @SqlResultSetMapping(
 *       name="CustomerDetailsResult",
 *       classes={
 *          @ConstructorResult(
 *               targetClass=com.acme.CustomerDetails.class,
 *                 columns={
 *                    @ColumnResult(name="id"),
 *                    @ColumnResult(name="name"),
 *                    @ColumnResult(name="orderCount"),
 *                    @ColumnResult(name="avgOrder", type=Double.class)
 *                    }
 *          )
 *       }
 *      )
 *
 * 
* * @see SqlResultSetMapping * @see ColumnResult * * @since 2.1 */ @Target({}) @Retention(RUNTIME) public @interface ConstructorResult { /** (Required) The class whose constructor is to be invoked. */ Class targetClass(); /** * (Required) The mapping of columns in the SELECT list to the arguments * of the intended constructor, in order. */ ColumnResult[] columns(); }




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