Hello,

I have a users table that has a autonumber identifier for the primary key and that is what the id is mapped to in hibernate. I have another column that is the username column which is unique and is a surrogate/natural key.

Often I am faced with having to load a user by their username (e.g. remember-me) and not by the autonumber field. However, because the username may occasionally change (albeit rarely) and because I prefer to use the numeric surrogate key for joins/collection loading I don't want to use the username as the primary hibernate identifier.

The issue that I am having is that I want to still be able to load/get objects by the natural key identifier so that they are put in the L2 cache. At this point I either have to consider:

1) Use the natural-key everywhere.
2) Try to use the query cache (from User where username=:username).
3) Cache the user objects manually outside of the Hibernate L2 cache.

It would be nice if I was actually able to do a load/get by a property (e.g.)
session.load( User.class, "username", username );

Does anybody have any suggestions/approaches to something like this!

Thanks in advance!

Sorry everybody, it looks like this is addressed already.

In the Hibernate 3.1.1 documentation:
15.9. Queries by natural identifier

You Hibernate guys thought of everything ;)

Thanks for the tip, I'm here searching for this exact same issue.

I don't mean to be picky, just a minor constructive feedback: surrogate is equivalent to "artificial", "invented", or something similar depending on your mother tongue (mine is Portuguese) :-)
Surrogate is the opposite of natural.