Re: [appengine-java] How to handle class version issues in DataStore

2012-03-12 Thread Jeff Schnitzer 
That's not quite correct - in the low-level datastore, this isn't an
issue because absent properties will simply be missing from the
Entity.

In Objectify, absent properties are ignored.  You can add fields of
primitive types without ill effect - they will simply have their
default values.  This is very useful when you add fields, or flag
fields as not-saved when they have certain values (ie the default).

I believe JPA/JDO will throw exceptions if you add a primitive type
field to your entity and there is no corresponding property in the
underlying loaded Entity.  This is very poor behavior, IMHO.  It
creates a very brittle structure.

Jeff

On Mon, Mar 12, 2012 at 4:12 AM, Matthew Jaggard  wrote:
> This answer also applies to the low level datastore and Objectify. I can
> only assume JPA works the same way.
>
> On Mar 12, 2012 7:40 AM, "andrew"  wrote:
>>
>> Nulls (Java), if the object can have null as a value. E.g. Integer can be
>> null, int cannot.
>>
>> I think this is explained in GAE/JDO documentation.
>>
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Re: [appengine-java] How to handle class version issues in DataStore

2012-03-12 Thread Matthew Jaggard 
This answer also applies to the low level datastore and Objectify. I can
only assume JPA works the same way.
On Mar 12, 2012 7:40 AM, "andrew"  wrote:

> Nulls (Java), if the object can have null as a value. E.g. Integer can be
> null, int cannot.
>
> I think this is explained in GAE/JDO documentation.
>
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>

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[appengine-java] How to handle class version issues in DataStore

2012-03-12 Thread andrew 
Nulls (Java), if the object can have null as a value. E.g. Integer can be null, 
int cannot.

I think this is explained in GAE/JDO documentation.

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[appengine-java] How to handle class version issues in DataStore

2012-03-11 Thread Yogesh Naik 
Hello,

I have a question related to App engine Data Store. Lets say I have a 
simple POJO class like this:
public class Employee implements Serializable {
private String name;
private Date birthDay;
...
...
}

I create an object of this class and store it in Data Store.

After this lets say if I had to modify the Employee class to include some 
additional fields.
Now, when I retrieve the old Employee object that I had stored in Data 
Store, do I get exception or object of new Employee class with new fields 
null?

Thanks in advance.

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