javax.persistence

## 注释类型 GeneratedValue

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

  Provides for the specification of generation strategies for the values of primary keys.

  The `GeneratedValue` annotation may be applied to a primary key property or field of an entity or mapped superclass in conjunction with the `Id` annotation. The use of the `GeneratedValue` annotation is only required to be supported for simple primary keys. Use of the `GeneratedValue` annotation is not supported for derived primary keys.

           Example 1:

           @Id
           @GeneratedValue(strategy=SEQUENCE, generator="CUST_SEQ")
           @Column(name="CUST_ID")
           public Long getId() { return id; }

           Example 2:

           @Id
           @GeneratedValue(strategy=TABLE, generator="CUST_GEN")
           @Column(name="CUST_ID")
           Long id;

  从以下版本开始:
    Java Persistence 1.0
  另请参阅:
    `Id`