https://github.com/javaee/jpa-spec: Java(TM) Persistence API 
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

/*******************************************************************************
 * 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;


Defines the types of primary key generation strategies. 

See Also:
  • GeneratedValue
Since:Java Persistence 1.0
/** 
 * Defines the types of primary key generation strategies. 
 *
 * @see GeneratedValue
 *
 * @since Java Persistence 1.0
 */
public enum GenerationType { 

    
Indicates that the persistence provider must assign 
primary keys for the entity using an underlying 
database table to ensure uniqueness.

/**
     * Indicates that the persistence provider must assign 
     * primary keys for the entity using an underlying 
     * database table to ensure uniqueness.
     */
    TABLE, 

    
Indicates that the persistence provider must assign 
primary keys for the entity using a database sequence.

/**
     * Indicates that the persistence provider must assign 
     * primary keys for the entity using a database sequence.
     */
    SEQUENCE, 

    
Indicates that the persistence provider must assign 
primary keys for the entity using a database identity column.

/**
     * Indicates that the persistence provider must assign 
     * primary keys for the entity using a database identity column.
     */
    IDENTITY, 

    
Indicates that the persistence provider should pick an 
appropriate strategy for the particular database. The 
AUTO generation strategy may expect a database 
resource to exist, or it may attempt to create one. A vendor 
may provide documentation on how to create such resources 
in the event that it does not support schema generation 
or cannot create the schema resource at runtime.

/**
     * Indicates that the persistence provider should pick an 
     * appropriate strategy for the particular database. The 
     * <code>AUTO</code> generation strategy may expect a database 
     * resource to exist, or it may attempt to create one. A vendor 
     * may provide documentation on how to create such resources 
     * in the event that it does not support schema generation 
     * or cannot create the schema resource at runtime.
     */
    AUTO
}