javax.persistence.OrderColumn Maven / Gradle / Ivy
/*
* 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.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
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".
*
* @return name
*/
String name() default "";
/**
* (Optional) Whether the database column is nullable.
*
* @return whether nullable
*/
boolean nullable() default true;
/**
* (Optional) Whether the column is included in SQL INSERT statements generated by the persistence
* provider.
*
* @return whether insertable
*/
boolean insertable() default true;
/**
* (Optional) Whether the column is included in SQL UPDATE statements generated by the persistence
* provider.
*
* @return whether updateable
*/
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.
*
* @return column definition
*/
String columnDefinition() default "";
}