I tried what you suggested and I get the following exception:
Datastore entity with kind ...has a null property named
voteDownCount. This property is mapped to ..., which cannot accept
null values.
It looks like I have some missing parameters in the
@Persistentannotation? I was thinking it would be the "nullValue"
parameter but it does not seem to be the case.
Does anyone know what would this be?
Thanks!
On Aug 16, 11:48 pm, Mujtaba Hassan <abatju...@gmail.com> wrote:
> This issue has been discussed on the forum.
>
> Just add your the new field in the ClassA and start your development, the
> old records will store null associated with the new field.
>
> On Mon, Aug 17, 2009 at 8:30 AM, victor <victoraco...@gmail.com> wrote:
>
> > This seems to be a common use case but I cannot seem to find the
> > answer to this in the forum. Let us say I have defined a persistent
> > class:
> > class A {
> > private String field;
> > //get set methods removed for clarity
> > }
>
> > Supposed that this class worked out fine and I have already deployed
> > my app and populated my tables with it. But then it just occurred to
> > me that I have to add a new field:
> > class A {
> > private String field;
> > private String newField;
> > //get set methods removed for clarity
> > }
>
> > What would be the best way to tackle this scenario? Can I just extend
> > "A" instead? -- but class extension seems to be poorly supported in
> > this JDO implementation. How do I migrate my old class versions?
>
> > I was thinking of putting class version on my classes and everytime I
> > update it I would do the following steps:
> > 1) Change the version ID of the class
> > 2) Migrate all the tables in the table by retrieving it, changing the
> > version ID, resave it with the new class.
>
> > Any pointers would be helpful.
>
> > Thanks!
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