have a table that there is no primary key. what ive done on my mapping file is I refer the ID to the column rownum so that I get a primary key. But hibernate return unknown column exceptions, which is I believe rownum exist on every table. What should I do to make rownum visible to the hibernate?


Thanks and regardz,
Allen Montejo

Rownum is only in Oracle, it's not present there in DB2 atleast, so you can't make use of it in Hibernate(atleast this is what i think).
Further, why is it that you don't want to define a Primary key for that table.
Relational laws state that every table should have a PK(although databases are too lenient in this regard and allow the creation of a table without a PK).

Anyways, i think you cannot use rownum because Hibernate will (should) not recognize it.

Don't use rownum as a primary key in Oracle. If you wish to automatically generate a primary key, you can use a sequence. Add something similar to this to your mapping file:

<class name="com.service.persist.domain.BssDaily" table="BSS_DAILY">
<id name="id" column="BSS_DAILY_ID">
<generator class="sequence">
<param name="sequence">bss_daily_seq</param>
</generator>
</id>

In my code, bss_daily_seq was an Oracle sequence, and bss_daily_id was a numeric column defined on oracle table bss_daily. "id" was a proprty in my Java object.

You will need to define the sequence in a tool such as Oracle Developer. Worked well in Hibernate 3.3.