Question

I have the below classes defined,

@Entity
@Idclass(Key.class)
public void ClassA {

...

@Id
@Version
private long version;

...
}

public class Key {
 ...
 private long version;
 ...
}

When compiling i get the below error,

“Unable to define @Version on an embedded class”

So is it possible to have a property which is part of the composite key defined as above also have the @Version. I did try adding the @version to the property in the Id class itself, but still it didn’t work.

thx in advance

Answer 1

It doesn’t make sense. The point of @Version is to define a field that the JPA engine will increment at each modification of the entity. The point of @Id is to define the primary key, which should be unique and immutable, and be used to identify an entity for its whole life. The @Version field should thus not be part of an ID.