jakarta.persistence.TableGenerator Maven / Gradle / Ivy
/*
* Copyright (c) 2008, 2023 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Gavin King - 3.2
// Lukas Jungmann - 2.2
// Linda DeMichiel - 2.1
// Linda DeMichiel - 2.0
package jakarta.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.ElementType.PACKAGE;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Repeatable;
/**
* Defines a primary key generator that may be referenced
* by name when a generator element is specified for the
* {@link GeneratedValue} annotation. A table generator
* may be specified on the entity class or on the primary
* key field or property. The scope of the generator name
* is global to the persistence unit (across all generator
* types).
*
* If no name is explicitly specified, and the annotation
* occurs on an entity class or primary key attribute of an
* entity class, then the name defaults to the name of the
* entity.
*
*
If no name is explicitly specified, and the annotation occurs
* on a package descriptor, then the annotation defines a recipe for
* producing a default generator when a {@link GeneratedValue}
* annotation of any program element in the annotated package has
* {@link GeneratedValue#strategy strategy=TABLE} and a defaulted
* {@linkplain GeneratedValue#generator generator name}. The name of
* this default generator is the defaulted generator name, and its
* other properties are determined by the members of the package
* {@code TableGenerator} annotation.
*
*
Example 1:
* {@snippet :
* @Entity
* public class Employee {
* ...
* @TableGenerator(
* name = "empGen",
* table = "ID_GEN",
* pkColumnName = "GEN_KEY",
* valueColumnName = "GEN_VALUE",
* pkColumnValue = "EMP_ID",
* allocationSize = 1)
* @Id
* @GeneratedValue(strategy = TABLE, generator = "empGen")
* int id;
* ...
* }
* }
*
*
Example 2:
* {@snippet :
* @Entity
* public class Address {
* ...
* @TableGenerator(
* table = "ID_GEN",
* pkColumnName = "GEN_KEY",
* valueColumnName = "GEN_VALUE",
* pkColumnValue = "ADDR_ID")
* @Id
* @GeneratedValue(strategy = TABLE)
* int id;
* ...
* }
* }
*
* @see GeneratedValue
*
* @since 1.0
*/
@Repeatable(TableGenerators.class)
@Target({TYPE, METHOD, FIELD, PACKAGE})
@Retention(RUNTIME)
public @interface TableGenerator {
/**
* (optional) A unique generator name that can be referenced
* by one or more classes to be the generator for id values.
*
Defaults to the name of the entity when the annotation
* occurs on an entity class or primary key attribute.
*/
String name() default "";
/**
* (Optional) Name of the table that stores the generated id
* values.
*
Defaults to a name chosen by persistence provider.
*/
String table() default "";
/**
* (Optional) The catalog of the table.
*
Defaults to the default catalog.
*/
String catalog() default "";
/** (Optional) The schema of the table.
*
Defaults to the default schema for user.
*/
String schema() default "";
/**
* (Optional) Name of the primary key column in the table.
*
Defaults to a provider-chosen name.
*/
String pkColumnName() default "";
/**
* (Optional) Name of the column that stores the last value
* generated.
*
Defaults to a provider-chosen name.
*/
String valueColumnName() default "";
/**
* (Optional) The primary key value in the generator table
* that distinguishes this set of generated values from
* others that may be stored in the table.
*
Defaults to a provider-chosen value to store in the
* primary key column of the generator table
*/
String pkColumnValue() default "";
/**
* (Optional) The initial value to be used to initialize the
* column that stores the last value generated.
*/
int initialValue() default 0;
/**
* (Optional) The amount to increment by when allocating id
* numbers from the generator.
*/
int allocationSize() default 50;
/**
* (Optional) Unique constraints that are to be placed on
* the table. These are only used if table generation is in
* effect. These constraints apply in addition to primary key
* constraints.
*
Defaults to no additional constraints.
*/
UniqueConstraint[] uniqueConstraints() default {};
/**
* (Optional) Indexes for the table. These are only used if
* table generation is in effect. Note that it is not necessary
* to specify an index for a primary key, as the primary key
* index is created automatically.
*
* @since 2.1
*/
Index[] indexes() default {};
/**
* (Optional) A SQL fragment appended to the generated DDL
* statement which creates this table.
*
* @since 3.2
*/
String options() default "";
}