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From No1UNo <je...@jerrycarter.org>
Subject Re: How to persist duplicate of an entity?
Date Fri, 14 Jan 2011 15:25:26 GMT

In a recent application, I was forced to resort to a copy constructor to explicitly make a
copy of the object.  I tried to reuse and re-persist an entity after making a few changes,
but any attempt to change the value of the @Id was blocked by OpenJPA.

On Jan 14, 2011, at 10:19 AM, Kevin Sutter [via OpenJPA] wrote:

> There are so many variables that can come into play with a scenario like 
> this... 
> 
> If you are only looking to populate the database and you don't care about 
> the actual Entity objects, then you could just populate a single Entity 
> instance.  In a loop, persist and commit this entity, update the key and 
> repeat.  If you are using a Version field, then you'll also have to reset 
> that each time. 
> 
> It all depends on the end game...  :-) 
> 
> Kevin 
> 
> On Fri, Jan 14, 2011 at 8:52 AM, Henno Vermeulen <[hidden email]>wrote: 
> 
> > The easiest way that I found to create a deep clone of an object graph is 
> > to use apache commons collections. 
> > SerializationUtils.deserialize(SerializationUtils.serialize(object)). 
> > 
> > Can of course also be used for a simple entity without relations. In anyway 
> > you have to watch out that you still set all primary keys to null. (May also 
> > not be most performant way.) 
> > 
> > Regards, 
> > Henno Vermeulen 
> > Huize Molenaar 
> > 
> > -----Oorspronkelijk bericht----- 
> > Van: Ognjen Blagojevic [mailto:[hidden email]] 
> > Verzonden: vrijdag 14 januari 2011 15:12 
> > Aan: [hidden email] 
> > Onderwerp: How to persist duplicate of an entity? 
> > 
> > Hi, 
> > 
> > Is there an easy way to create duplicate of an entity? 
> > 
> > I want to read entity from the DB, and then persist (almost) identical 
> > copy. Every field should be the same, except primary key. 
> > 
> > I know I could probably use BeanUtils.copyProperties, but is there 
> > OpenJPA preffered way to do the duplication? 
> > 
> > Regards, 
> > Ognjen 
> > 
> 
> 
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