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From Rick Hillegas <rick.hille...@oracle.com>
Subject Re: Sequences as default values for a column
Date Mon, 11 Jul 2011 14:00:00 GMT
Hi Ryan,

I don't know whether you have considered identity columns. Identity 
columns may give you what you need. See the Derby Reference Guide topics 
" CREATE TABLE statement" -> "column-definition" -> 
"generated-column-spec". Right now, identity columns provide less 
concurrency than sequences do. However, identity columns should catch up 
to sequences in 10.8.2 due to the work on 
https://issues.apache.org/jira/browse/DERBY-4437

Hope this helps,
-Rick

On 7/8/11 12:59 PM, Ryan McFall wrote:
> >From what I can see in the Derby documentation, it's not possible to 
> specify the value of a sequence as the default value for a column.  Is 
> my reading of this correct?
>
> I've seen solutions online for Oracle, which also supports sequences, 
> that suggest using a before insert trigger to modify the value of a 
> column with a sequence value if the value is not specified.  This 
> seems like it's more work than it should be; specifying it as a 
> default in the table definition makes much more sense to me.
>
> Thanks for any insights you have,
> Ryan
>
> -- 
> Ryan McFall
> Associate Professor of Computer Science
> Hope College
> Holland, MI  49423
> Email: mcfall@hope.edu <mailto:mcfall@hope.edu>
> Phone: 616-395-7952
> Fax: 616-395-7123
> http://www.hope.edu/cs/mcfall/


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