[
https://issues.apache.org/jira/browse/DERBY-6882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15252362#comment-15252362
]
Aleksei Kovura edited comment on DERBY-6882 at 4/23/16 4:17 AM:
----------------------------------------------------------------
Some assistance would be nice actually. I tried checking out derby code:
mkdir derby ; svn co https://svn.apache.org/repos/asf/db/derby/code/trunk derby
... and switching to a revision you specified in the next post (r1740299):
svn up -r1740299
It builds successfully, but I end up with "10.13.0.0 alpha" version of jars in
jars/sane/. It's supposed to be some sort of 10.12.xx, right?
------------- EDIT: -------------
It seems JIRA is still in Lockdown, so I'll edit this comment because I can't
post a new one.
I've built 10.12 branch. Below is an example where this new functionality
doesn't quite work as expected. If after this example I do ALTER TABLE ACTIONS
ALTER COLUMN id RESTART WITH 5; then the table starts working normally. It
would be more handy if Derby automatically handled ID gaps and skipped already
existing IDs though. If that won't be implemented for whatever reason, then it
should be documented that users should restart ID generation according to their
current max ID value, increment and so on (I can contribute to documention).
What do you think?
------- USAGE SCENARIO --------
java -jar derbyrun.jar ij
ij version 10.12
ij> connect 'jdbc:derby:sample_alter;create=true';
ij> CREATE TABLE APP."ACTIONS" (id INTEGER NOT NULL GENERATED ALWAYS AS
IDENTITY CONSTRAINT PK_ACTION_ID PRIMARY KEY,description VARCHAR(128) NOT NULL);
0 rows inserted/updated/deleted
ij> INSERT INTO ACTIONS (description) VALUES ('action1');
1 row inserted/updated/deleted
ij> INSERT INTO ACTIONS (description) VALUES ('action2');
1 row inserted/updated/deleted
ij> select * from actions;
ID |DESCRIPTION
--------------------------------------------------------------------------------------------------------------------------------------------
1 |action1
2 |action2
2 rows selected
ij> ALTER TABLE ACTIONS ALTER COLUMN id SET GENERATED BY DEFAULT;
0 rows inserted/updated/deleted
ij> INSERT INTO ACTIONS (id, description) VALUES (4, 'action4');
1 row inserted/updated/deleted
ij> select * from actions;
ID |DESCRIPTION
--------------------------------------------------------------------------------------------------------------------------------------------
1 |action1
2 |action2
4 |action4
3 rows selected
ij> ALTER TABLE ACTIONS ALTER COLUMN id SET GENERATED ALWAYS;
0 rows inserted/updated/deleted
ij> INSERT INTO ACTIONS (description) VALUES ('action2');
1 row inserted/updated/deleted
ij> select * from actions;
ID |DESCRIPTION
--------------------------------------------------------------------------------------------------------------------------------------------
1 |action1
2 |action2
4 |action4
3 |action2
4 rows selected
ij> INSERT INTO ACTIONS (description) VALUES ('action2');
ERROR 23505: The statement was aborted because it would have caused a duplicate
key value in a unique or primary key constraint or unique index identified by
'PK_ACTION_ID' defined on 'ACTIONS'.
was (Author: alex k.):
Some assistance would be nice actually. I tried checking out derby code:
mkdir derby ; svn co https://svn.apache.org/repos/asf/db/derby/code/trunk derby
... and switching to a revision you specified in the next post (r1740299):
svn up -r1740299
It builds successfully, but I end up with "10.13.0.0 alpha" version of jars in
jars/sane/. It's supposed to be some sort of 10.12.xx, right?
> Add functionality to ALTER TABLE: switch from GENERATED ALWAYS to GENERATED
> BY DEFAULT
> --------------------------------------------------------------------------------------
>
> Key: DERBY-6882
> URL: https://issues.apache.org/jira/browse/DERBY-6882
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 10.12.1.1
> Reporter: Aleksei Kovura
> Assignee: Rick Hillegas
> Labels: features
> Attachments: derby-6882-01-aa-initialCode.diff,
> derby-6882-01-bb-withTests.diff, derby-6882-02-aa-port_1738368_to_10.12.diff
>
>
> I'm trying to import data from another Derby database with foreignViews tool
> because system tables got corrupted somehow (see
> https://issues.apache.org/jira/browse/DERBY-6876). Tables contain generated
> ID columns (created as "GENERATED ALWAYS"). Importing data and allowing Derby
> to generate new IDs in generated columns will break relationships between
> tables (old tables have counter gaps there due to deletes - IDs won't match).
> For a clean import without breaking DDL information in DB version control I
> would like to be able to switch between generated types as follows:
>
> ALTER TABLE table1 ALTER COLUMN col1 SET GENERATED BY DEFAULT [ AS IDENTITY]
> ALTER TABLE table1 ALTER COLUMN col1 SET GENERATED ALWAYS [ AS IDENTITY]
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
