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`

- - ### 可选元素概要

    可选元素
    限定符和类型 | 可选元素和说明
    --- | ---
    `java.lang.String` | `generator` 已过时。
    `GenerationType` | `strategy` 已过时。

- - ### 元素详细资料

    - #### strategy

          @Deprecated
          public abstract GenerationType strategy

      已过时。
      (Optional) The primary key generation strategy that the persistence provider must use to generate the annotated entity primary key.
      返回:
        GenerationType
      默认值:
        javax.persistence.GenerationType.AUTO

  - - #### generator

          @Deprecated
          public abstract java.lang.String generator

      已过时。
      (Optional) The name of the primary key generator to use as specified in the SequenceGenerator or TableGenerator annotation.

      Defaults to the id generator supplied by persistence provider.

      返回:
        String
      默认值:
        ""