Hibernate JPA序列（非Id）(Hibernate JPA Sequence (non-Id))

 对于不是标识符的某些列可能使用DB序列， 不是组合标识符的一部分 ？ 
 
 我使用hibernate作为jpa提供程序，我有一个表，它有一些列是生成值（使用序列），尽管它们不是标识符的一部分。 
 
 我想要的是使用一个序列为一个实体创建一个新的值，其中序列的列不是主键的一部分： 
 
@Entity
@Table(name = "MyTable")
public class MyEntity {

    //...
    @Id //... etc
    public Long getId() {
        return id;
    }

   //note NO @Id here! but this doesn't work...
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "myGen")
    @SequenceGenerator(name = "myGen", sequenceName = "MY_SEQUENCE")
    @Column(name = "SEQ_VAL", unique = false, nullable = false, insertable = true, updatable = true)
    public Long getMySequencedValue(){
      return myVal;
    }

}
 
 然后当我这样做： 
 
em.persist(new MyEntity());
 
 该ID将被生成，但mySequenceVal属性也将由我的JPA提供者生成。 
 
 只是为了使事情清晰：我希望Hibernate生成mySequencedValue属性的值。 我知道Hibernate可以处理数据库生成的值，但是我不想使用触发器或Hibernate以外的其他任何东西来生成我的属性的值。 如果Hibernate可以为主键生成值，为什么不能生成一个简单的属性？ 

Is it possible to use a DB sequence for some column that is not the identifier/is not part of a composite identifier? 
 
I'm using hibernate as jpa provider, and I have a table that has some columns that are generated values (using a sequence), although they are not part of the identifier.
 
What I want is to use a sequence to create a new value for an entity, where the column for the sequence is NOT (part of) the primary key:
 
@Entity
@Table(name = "MyTable")
public class MyEntity {

    //...
    @Id //... etc
    public Long getId() {
        return id;
    }

   //note NO @Id here! but this doesn't work...
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "myGen")
    @SequenceGenerator(name = "myGen", sequenceName = "MY_SEQUENCE")
    @Column(name = "SEQ_VAL", unique = false, nullable = false, insertable = true, updatable = true)
    public Long getMySequencedValue(){
      return myVal;
    }

}
 
Then when I do this:
 
em.persist(new MyEntity());
 
the id will be generated, but the mySequenceVal property will be also generated by my JPA provider.
 
Just to make things clear: I want Hibernate to generate the value for the mySequencedValue property. I know Hibernate can handle database-generated values, but I don't want to use a trigger or any other thing other than Hibernate itself to generate the value for my property. If Hibernate can generate values for primary keys, why can't it generate for a simple property?

原文：https://stackoverflow.com/questions/277630