javax.persistence

Annotation Type OrderColumn

@Target(value={METHOD,FIELD})
 @Retention(value=RUNTIME)
public @interface OrderColumn

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

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
java.lang.String	columnDefinition (Optional) The SQL fragment that is used when generating the DDL for the column.
boolean	insertable (Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
java.lang.String	name (Optional) The name of the ordering column.
boolean	nullable (Optional) Whether the database column is nullable.
boolean	updatable (Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.

Element Detail

name

public abstract java.lang.String name

(Optional) The name of the ordering column. Defaults to the concatenation of the name of the referencing property or field; "_"; "ORDER".

Default:

""

nullable

public abstract boolean nullable

(Optional) Whether the database column is nullable.

Default:

true

insertable

public abstract boolean insertable

(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.

Default:

true

updatable

public abstract boolean updatable

(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.

Default:

true

columnDefinition

public abstract java.lang.String columnDefinition

(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.

Default:

""