Home/ Questions/Q 3339200
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-18T00:27:53+00:00

First off, we are using JPA 2.0 and Hibernate 3.5 as persistence provider on

  • 0

First off, we are using JPA 2.0 and Hibernate 3.5 as persistence provider on a PostgreSQL database.

We successfully use the sequence of the database via the JPA 2.0 annotations as an auto-generated value for single-field-surrogate-keys and all works fine.

Now we are implementing a bi-temporal database-scheme that requires a mixed key in the following manner:

Table 1:
id             (pk, integer, auto-generated-sequence)
validTimeBegin (pk, dateTime)
validTimeEnd   (dateTime)
firstName      (varChar)

Now we have a problem. You see, if we INSERT a new element, the field id is auto-generated and that’s fine. Only, if we want to UPDATE the field within this scheme, then we have to change the validTimeBegin column WITHOUT changing the id-field and insert it as a new row like so:

BEFORE THE UPDATE OF THE ROW:

|---|-------------------------|-------------------------|-------------------|
| id|      validTimeBegin     |       validTimeEnd      |     firstName     |
|---|-------------------------|-------------------------|-------------------|
|  1| 2010-05-01-10:00:00.000 |                    NULL |            Gerald |
|---|-------------------------|-------------------------|-------------------|

AFTER THE UPDATE OF THE ROW happening at exactly 2010-05-01-10:35:01.788 server-time:

(we update the person with the id:1 to reflect his new first name...)
|---|-------------------------|-------------------------|-------------------|
| id|      validTimeBegin     |       validTimeEnd      |     firstName     |
|---|-------------------------|-------------------------|-------------------|
|  1| 2010-05-01-10:00:00.000 | 2010-05-01-10:35:01.788 |            Gerald |
|---|-------------------------|-------------------------|-------------------|
|  1| 2010-05-01-10:35:01.788 |                    NULL |             Jerry |
|---|-------------------------|-------------------------|-------------------|

So our problem is, that this doesn’t work at all using an auto-generated-sequence for the field id because when inserting a new row then the id ALWAYS is auto-generated although it really is part of a composite key which should sometimes behave differently.

So my question is:
Is there a way to tell hibernate via JPA to stop auto-generating the id-field in the case I want to generate a new variety of the same person and go on as usual in every other case or do I have to take over the whole id-generation with custom code?

Thanks in advance,
Gerald

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    So… Some time has passed now without any comments and now I’m pretty sure that there’s no way to do that. In fact it’s one of the reasons why developers start generating their own unique keys for databases via their own id-generators on the application-side.
    This way the database never even knows about such a thing as a surrogate key; It just receives it.

    By the way:
    We solved our problem by implementing our own methods for the task of updating such rows. These methods now are OR-Mapper dependent and in no way JPA 2.0 compliant but JPA just doesn’t support an annotation for such behavior.

    • 0