[news.eclipse.rt.eclipselink] Re: Calculations of field values using oth

[Philipp Kursawe <phil.kursawe@xxxxxxxxx>]

James wrote:
> You could change this to a query instead of a persistence attribute.

What you mean by that? How would I annotate that or create this query?

> If you need to map it, you could use a TransformationMapping in 
> EclipseLink, or use a postBuild event to query the data.  You could also 
> just lazy initialize the field using a query.
>
> Another solution would be define a database view that include the 
> computed values and map your object to the view.
I am doing that right now, it might be the most performant solution.
But anyway I am interested, in case the DB does not support views, how I 
would use a TransformationMapping in my particular case. Do you have an 
example of that for me?

Thanks,
Phil