javax.persistence.OrderColumn Maven / Gradle / Ivy
/*******************************************************************************
* 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;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
/**
* Specifies a column that is used to maintain the persistent order of
* a list. The persistence provider is responsible for maintaining the
* order upon retrieval and in the database. The persistence provider
* is responsible for updating the ordering upon flushing to the
* database to reflect any insertion, deletion, or reordering
* affecting the list.
*
* The OrderColumn annotation is specified on a
* OneToMany or ManyToMany relationship or on an element
* collection. The OrderColumn annotation is specified on
* the side of the relationship that references the collection that is
* to be ordered. The order column is not visible as part of the state
* of the entity or embeddable class.
*
*
The {@link OrderBy} annotation should be used for ordering that
* is visible as persistent state and maintained by the
* application. The OrderBy annotation is not used when
* OrderColumn is specified.
*
*
The order column must be of integral type. The persistence
* provider maintains a contiguous (non-sparse) ordering of the values
* of the order column when updating the association or element collection.
* The order column value for the first element is 0.
*
*
*
* Example:
*
* @Entity
* public class CreditCard {
*
* @Id long ccNumber;
*
* @OneToMany // unidirectional
* @OrderColumn
* List<CardTransaction> transactionHistory;
* ...
* }
*
*
*
* @see OrderBy
*
* @since Java Persistence 2.0
*/
@Target( { METHOD, FIELD })
@Retention(RUNTIME)
public @interface OrderColumn {
/** (Optional) The name of the ordering column.
* Defaults to the concatenation of the name of the
* referencing property or field; "_"; "ORDER".
*/
String name() default "";
/** (Optional) Whether the database column is nullable. */
boolean nullable() default true;
/**
* (Optional) Whether the column is included in SQL INSERT statements
* generated by the persistence provider.
*/
boolean insertable() default true;
/**
* (Optional) Whether the column is included in SQL UPDATE statements
* generated by the persistence provider.
*/
boolean updatable() default true;
/**
* (Optional) The SQL fragment that is used when generating the DDL for the
* column. Defaults to generated SQL to create a column of the inferred type.
*/
String columnDefinition() default "";
}