We are introducing Hibernate Envers in our application.
Now, we want to store an initial revision of all out audited entities in the audit-tables. I thought I just could save the entities once via JPA, but Envers checks for modifications and does not save a new version.
I don’t want to make any arbitrary changes.
Is there a recommended way to create an initial version of all audited entities? Or force Envers to save a version even if there are no changes? Or something similar?
Or is SQL the only (and recommended?) way to do this?
Why would you want to save the initial version if it is the same as the previous one? There should be no need for creating that, but if you want that, I think your only option is to write that with SQL directly or change something arbitrary.
There is no previous one. It is the “current” one. Data was imported with SQL loading and before we had Envers working.
So now, if I change something, the new version is saved in the audit-tables. But I have no way to find out the version before.
There is the need, definitely. And I am not the only one. But I did not find a nice solution for now.
We are using MySQL, what I came up with now, is, for each audited table (we save the user which changed the data, too, so we have a revinfo table):
set @i=(select max(id) from revinfo);
insert into table_aud (id, rev, revtype, ...all other columns)
@i + (ROW_NUMBER() over (ORDER BY id)) as rev,
0 as revtype,
...all other columns
insert into revinfo
select rev, NOW() as timestamp, 'user' as username from table_aud
where rev > @i;
Not very nice, and it has to be done for any audited table, but works.
I had to increase the value in table hibernate_sequence, too.
update hibernate_sequence set next_val = (select max(id)+1 from revinfo);