/******************************************************************************* | |
* 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.FIELD; | |
import static java.lang.annotation.ElementType.METHOD; | |
import static java.lang.annotation.RetentionPolicy.RUNTIME; | |
/** | |
* Specifies the mapping for the key column of a map whose | |
* map key is a basic type. If the <code>name</code> element is not specified, it | |
* defaults to the concatenation of the following: the name of the | |
* referencing relationship field or property; "_"; "KEY". | |
* | |
* <pre> | |
* Example: | |
* | |
* @Entity | |
* public class Item { | |
* @Id int id; | |
* ... | |
* @ElementCollection | |
* @MapKeyColumn(name="IMAGE_NAME") | |
* @Column(name="IMAGE_FILENAME") | |
* @CollectionTable(name="IMAGE_MAPPING") | |
* Map<String, String> images; // map from image name to filename | |
* ... | |
* } | |
* </pre> | |
* @since Java Persistence 2.0 | |
*/ | |
@Target( { METHOD, FIELD }) | |
@Retention(RUNTIME) | |
public @interface MapKeyColumn { | |
/** | |
* (Optional) The name of the map key column. The table in which it is found | |
* depends upon the context. If the map key is for an element collection, | |
* the map key column is in the collection table for the map value. If the | |
* map key is for a ManyToMany entity relationship or for a OneToMany entity | |
* relationship using a join table, the map key column is in a join table. | |
* If the map key is for a OneToMany entity relationship using a foreign key | |
* mapping strategy, the map key column is in the table of the entity that | |
* is the value of the map. | |
* <p> Defaults to the concatenation of the following: the name of | |
* the referencing relationship field or property; "_"; "<code>KEY</code>". | |
*/ | |
String name() default ""; | |
/** | |
* (Optional) Whether the column is a unique key. This is a | |
* shortcut for the <code>UniqueConstraint</code> annotation | |
* at the table level and is useful for when the unique key | |
* constraint corresponds to only a single column. This | |
* constraint applies in addition to any constraint entailed | |
* by primary key mapping and to constraints specified at the | |
* table level. | |
*/ | |
boolean unique() default false; | |
/** (Optional) Whether the database column is nullable. */ | |
boolean nullable() default false; | |
/** | |
* (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. | |
* <p> Defaults to the generated SQL to create a | |
* column of the inferred type. | |
* | |
*/ | |
String columnDefinition() default ""; | |
/** (Optional) The name of the table that contains the column. | |
* | |
* <p> Defaults: If the map key is for an element collection, | |
* the name of the collection table for the map value. If the | |
* map key is for a OneToMany or ManyToMany entity | |
* relationship using a join table, the name of the join table | |
* for the map. If the map key is for a OneToMany entity | |
* relationship using a foreign key mapping strategy, the name | |
* of the primary table of the entity that is the value of the | |
* map. | |
*/ | |
String table() default ""; | |
/** | |
* (Optional) The column length. (Applies only if a string-valued column is | |
* used.) | |
*/ | |
int length() default 255; | |
/** | |
* (Optional) The precision for a decimal (exact numeric) column. (Applies | |
* only if a decimal column is used.) | |
* | |
*<p> Default: 0. (The value must be set by the developer.) | |
*/ | |
int precision() default 0; // decimal precision | |
/** | |
* (Optional) The scale for a decimal (exact numeric) column. (Applies only | |
* if a decimal column is used.) | |
*/ | |
int scale() default 0; // decimal scale | |
} |