/*
 * 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.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 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 Also:
OrderBy
Since:
Java Persistence 2.0/**
 * 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.
 * <p>
 * The <code>OrderColumn</code> annotation is specified on a OneToMany or ManyToMany relationship or on an
 * element collection. The <code>OrderColumn</code> 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.
 * <p>
 * The {@link OrderBy} annotation should be used for ordering that is visible as persistent state and
 * maintained by the application. The <code>OrderBy</code> annotation is not used when
 * <code>OrderColumn</code> is specified.
 * <p>
 * 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.
 * <p>
 * <pre>
 *
 *    Example:
 *
 *    &#064;Entity
 *    public class CreditCard {
 *
 *       &#064;Id long ccNumber;
 *
 *       &#064;OneToMany  // unidirectional
 *       &#064;OrderColumn
 *       List&#060;CardTransaction&#062; transactionHistory;
 *       ...
 *    }
 *
 * </pre>
 *
 * @see OrderBy
 * @since Java Persistence 2.0
 */
@Target({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".
Returns:
name/**
   * (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.
Returns:
whether nullable/**
   * (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.
Returns:
whether insertable/**
   * (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.
Returns:
whether updateable/**
   * (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.
Returns:
column definition/**
   * (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 "";
}