jakarta.persistence.ColumnResult Maven / Gradle / Ivy
/*
* Copyright (c) 2008, 2023 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},
* {@link NamedNativeQuery}, or {@link ConstructorResult}
* annotation to map a column of the SELECT list of a SQL query.
*
* The {@link #name} element references the name of a column
* in the SELECT list — i.e., column alias, if applicable.
* Scalar result types can be included in the query result by
* specifying this annotation in the metadata.
*
*
Example:
* {@snippet :
* 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");
*
* @SqlResultSetMapping(
* name = "OrderResults",
* entities = {
* @EntityResult(
* entityClass = com.acme.Order.class,
* fields = {
* @FieldResult(name = "id", column = "order_id"),
* @FieldResult(name = "quantity", column = "order_quantity"),
* @FieldResult(name = "item", column = "order_item")
* })
* },
* columns = {
* @ColumnResult(name = "item_name")
* })
* }
*
* @see SqlResultSetMapping
* @see NamedNativeQuery
* @see ConstructorResult
*
* @since 1.0
*/
@Target({})
@Retention(RUNTIME)
public @interface ColumnResult {
/**
* (Required) The name of a column in the SELECT clause of a SQL query
*/
String name();
/**
* (Optional) The Java type to which the column type is to be mapped.
* If the {@code type} element is not specified, the default JDBC type
* mapping for the column is used.
* @since 2.1
*/
Class type() default void.class;
}