Thanks for the reply, Rick. I was using identify columns, but then found that Oracle does not support identity columns, only sequences. Since I'm looking for cross-database portability, I'm sticking with sequences - I'm using Hibernate, and it will automatically choose between a sequence and using a table to simulate a sequence based on capabilities of the DB.
> From: Rick Hillegas <email@example.com>
Subject: Re: Sequences as default values for a column
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,
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,
Associate Professor of Computer Science
Holland, MI 49423