Yep, still need to override the derived attribute's getter and mimic/duplicate 
the concatenation (in this case) to ensure it reflects the uncommitted changes, 
very noticeable when you have a new object that hasn't been saved to the 
backing store!

The big gains from this type of attribute become apparent when building 
qualifiers..

Sharpy.

On 24/11/2010, at 10:20 PM, John Larson wrote:

> A note about those columns, they are only evaluated during fetch since their 
> content is generated in the SQL. So if your user updates their last name, the 
> full name won't update until the changes are committed and then fetched 
> again. 
> 
> Just a head's up. 
> 
> John 
> 
> Sent from my iPhone
> 
> On Nov 24, 2010, at 1:37 AM, Theodore Petrosky <[email protected]> wrote:
> 
>> I am reading the Red Webobject 5.0 book and I think I finally understand the 
>> small section on creating an attribute the is derived. 
>> 
>> (I am using postgresql as the backend)
>> 
>> so my User entity has a firstName and a lastName. I created an attribute 
>> called 'theFullName' as derived "firstName || ' ' || lastName", in the 
>> advanced tab, I choose "Read Only".
>> 
>> i assumed that would be enough, however I needed to also select 'allows 
>> null' in the basic tab. if I didn't, User.createUser(yada, yada); required a 
>> 'theFullName' attribute.
>> 
>> My assumption was that as the column is derived and read only, I thought the 
>> column was special and shouldn't need the 'allows null' selection.
>> 
>> so, did I do it correctly?
>> as the column is a derived column and read only, why do I need to add 
>> 'allows null'?
>> 
>> I have been creating all these derivatives in java in my User.java file, but 
>> I thought I would expand my understanding and play with some features.
>> 
>> now on to stored proceedures.
>> 
>> Ted
>> 
>> 
>> 
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