Load sparsely populated object?

hay7777 · **Joined:** Wed Jul 21, 2004 6:50 pm **Posts:** 27

Hi,

Can Hibernate just load part of an object? ie I want the object back, but only sparsely populated with a few of the fields?

cheers,

David

anthony · **Posted:** Tue Apr 19, 2005 12:40 pm

search wiki

you may use inheritance or lazy property (H3)

hay7777 · **Joined:** Wed Jul 21, 2004 6:50 pm **Posts:** 27

Hi Anthony,

Thanks for your reply. Maybe you wouldn't mind explaining a little deeper...

Inheritance is out for us, I think, as the domain object just has lots of properties. Or am I missing something?

From what I've seen looking at lazy loading of properties, it seems somewhat discouraged? It seems to me that if the domain object is large, obtaining a sparsely populated one (say for a particular UI view) would be a common requirement.

Please let me know if I am not understanding this.

cheers,

David

anthony · **Posted:** Tue Apr 19, 2005 1:45 pm

are you asking about a big number of properties or big number of associations?

maybe this link will help you
http://www.hibernate.org/41.html

about lazy property, we aren't fan but that can help.

hay7777 · **Joined:** Wed Jul 21, 2004 6:50 pm **Posts:** 27

Hi Anthony,

Perhaps I should give more detail:

We have an object that has a Map of other objects, each of which can have a Map of other objects!

So, for our UI especially, there are times when we just want one of our main objects sparsely populated with only one of the first Maps, with only a few of its Maps.

We don't really want to perform a query and create the object ourselves - we'd like to specify what to load in the query and have Hibernate create the main object with the columns that are specified, which will relate to the other maps.

Is that any clearer?! What's the suggested way to handle this in Hibernate?

thanks very much,

David

anthony · **Posted:** Tue Apr 19, 2005 2:57 pm

next time, start explaining that ;)

map are collections, you can use lazy loading on it and eager fetch the collections you want using query.

All this is explained in the forum, in Hibernate in action...

please don't reply again until you've read
http://www.hibernate.org/ForumMailingli ... AskForHelp

i have no more time to "imagine" what your real problem is, sorry.

hay7777 · **Joined:** Wed Jul 21, 2004 6:50 pm **Posts:** 27

Sorry - I was actually asking for another part of the team, and didn't realise exactly what was happening til you prompted me!