CODEWITHSUNDEEP
javaspringhibernate
kenny
kenny

Reputation: 1247

Hibernate needed values to save a child

I currently have working code to save children to a parent entity. But I'm wondering if I'm doing things right since I now have an overload on select statements going thru hibernate. I do use caching so atm I don't have delay problems but I'm wondering if I can't be more efficient. Take this little extract as example

MbaLog.debugLog(logger, "Saving CodeType");
Site site = codeType.getSite();
if (site != null && site.isProxy())
    codeType.setSite(siteRepository.loadSiteById(site.getId()));
Long recordId = codeRepository.saveCodeType(codeType);

I have an entity CodeType that I'm saving that has a child Site. This child is passed to the method as a proxy object with just it's id filled in. Then I fetch a fully loaded Site object from the database and set it on codetype. Next up I save the codeType with the sessionfactory of hibernate to the database (code not visible here, but it's behind the codeRepository).

This works but I'm loading a full site, that has childs of it's own so I see at least 5 queries passing before the insert. I could put a lot of stuff lazy on site, but for the time being I rather not do that due to possible code complications in deeper layers. I had to learn hibernate and JPA on the job and never had much training from experts in the past. So I'm wondering, is there a shortcut to save the site on codetype ? Do I need to have it fully loaded or is the id enough ? or just the id and version (I'm using @version annotation on all my entities for optimistic locking)

Thanks in advance

Upvotes: 0

Views: 81

Answers (2)

rvcoutinho
rvcoutinho

Reputation: 336

If all you want to persist is the relationship between Site and CodeType, a lazy instance is probably enough. So you could use EntityManager.getReference() (lazy load) instead of EntityManager.find().

Upvotes: 1

JB Nizet
JB Nizet

Reputation: 691655

Instead of using Session.get() (or EntityManager.find()) to get a reference to the SIte entity, use Session.load() (or EntityManager.getReference()) to get this reference.

These methods will return a lazy-loaded proxy on the entity rather than executing a query to get the data of the site.

Upvotes: 1

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