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From "TomohitoNakayama" <tomon...@basil.ocn.ne.jp>
Subject DERBY-318(Re: DERBY-308 just be done and .... (Re: [jira] Updated: (DERBY-308) Modify dblook to support "GENERATED BY DEFAULT AS IDENTITY"))
Date Mon, 30 May 2005 22:17:47 GMT
Hello.

Army wrote :
> The safest (consistent) thing to do is to return NULL for columns that are 
> GENERATED BY DEFAULT, so I think that's what I would vote for (despite my 
> initial email saying otherwise).  But that's just me--I hope anyone who 
> feels otherwise will post saying so...

My thought ...

I concluded as next.
Thinking "GENERATED BY DEFAULT AS IDENTITY" is a kind of default,
returning not null value for that column does not cause problem.
On the contrast , returning null value for column of "GENERATED BY DEFAULT 
AS IDENTITY"
may cause some inconsistency, because the column is a column with special 
default value.

Of cource, regression test is neccesary,
because there remains anxiety.

Best regards.

/*

         Tomohito Nakayama
         tomonaka@basil.ocn.ne.jp
         tomohito@rose.zero.ad.jp

         Naka
         http://www5.ocn.ne.jp/~tomohito/TopPage.html

*/
----- Original Message ----- 
From: "Army" <qozinx@sbcglobal.net>
To: "Derby Development" <derby-dev@db.apache.org>
Sent: Tuesday, May 31, 2005 1:39 AM
Subject: Re: DERBY-308 just be done and .... (Re: [jira] Updated: 
(DERBY-308) Modify dblook to support "GENERATED BY DEFAULT AS IDENTITY")


> TomohitoNakayama wrote:
>> Hello.
>>
>> I consider this issue in last weekend and agree your opinion in general.
>> "in general" means that I think "GENERATED_BY_DEFAULT" is better.
>>
>> To think manipulating the value in some script, no space in this value 
>> would be better.
>> How do others think ?
>
> The only issue with this is consistency.  For a column that's "GENERATED 
> ALWAYS", Derby currently returns NULL for the default text.  In order to 
> be consistent, I think we should have the same behavior for the two types 
> of columns: either return NULL for the default text in both cases, or else 
> return some constant string.
>
> But that said, if we change GENERATED ALWAYS columns to return a non-null 
> value (such as "GENERATED_ALWAYS"), then there's the chance that we 
> introduce a regression: any users of the 10.0 release who expect a NULL 
> will now get different behavior.  I don't know if that's acceptable...?
>
> The safest (consistent) thing to do is to return NULL for columns that are 
> GENERATED BY DEFAULT, so I think that's what I would vote for (despite my 
> initial email saying otherwise).  But that's just me--I hope anyone who 
> feels otherwise will post saying so...
>
> Army
>
>
>
>
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