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http://issues.apache.org/jira/browse/DERBY-504?page=comments#action_12322909 ]
Knut Anders Hatlen commented on DERBY-504:
------------------------------------------
About the 10.1 patch:
1) Yes, it includes the cleanup patch.
2) No, it is not generated from an svn merge command, but it could be done. I
incorrectly assumed that it wouldn't work since applying the trunk patch
directly failed. Seems like subversion is smarter than me... ;)
Applying this command will merge the committed changes into 10.1:
svn merge -r 267238:267239 mytrunkdir my10.1dir
This doesn't include the cleanup patch, but it will fix the bug. The cleanup
patch could be applied directly, but it is not important in the 10.1 backport.
There is one difference between my 10.1 patch and the svn merge. One of the
j9_22 canons
(java/testing/org/apache/derbyTesting/functionTests/master/j9_22/distinct.out)
is different. Since I haven't tested the j9_{13,22} files, that canon must be
checked by someone else anyway.
> SELECT DISTINCT returns duplicates when selecting from subselects
> -----------------------------------------------------------------
>
> Key: DERBY-504
> URL: http://issues.apache.org/jira/browse/DERBY-504
> Project: Derby
> Type: Bug
> Components: SQL
> Versions: 10.2.0.0
> Environment: Latest development sources (SVN revision 232227), Sun JDK 1.5,
> Solaris/x86
> Reporter: Knut Anders Hatlen
> Assignee: Knut Anders Hatlen
> Priority: Minor
> Attachments: DERBY-504-10.1-unix.diff, DERBY-504-10.1-windows.diff,
> DERBY-504-10.1.stat, DERBY-504-cleanup.diff, DERBY-504-cleanup.stat,
> DERBY-504.diff, DERBY-504.stat, DERBY-504_b.diff, DERBY-504_b.stat,
> DERBY-504_c-CRLF.diff, DERBY-504_c-CRLF.diff, DERBY-504_c.diff,
> DERBY-504_c.stat
>
> When one performs a select distinct on a table generated by a subselect,
> there sometimes are duplicates in the result. The following example shows the
> problem:
> ij> CREATE TABLE names (id INT PRIMARY KEY, name VARCHAR(10));
> 0 rows inserted/updated/deleted
> ij> INSERT INTO names (id, name) VALUES
> (1, 'Anna'), (2, 'Ben'), (3, 'Carl'),
> (4, 'Carl'), (5, 'Ben'), (6, 'Anna');
> 6 rows inserted/updated/deleted
> ij> SELECT DISTINCT(name) FROM (SELECT name, id FROM names) AS n;
> NAME
> ----------
> Anna
> Ben
> Carl
> Carl
> Ben
> Anna
> Six names are returned, although only three names should have been returned.
> When the result is explicitly sorted (using ORDER BY) or the id column is
> removed from the subselect, the query returns three names as expected:
> ij> SELECT DISTINCT(name) FROM (SELECT name, id FROM names) AS n ORDER BY
> name;
> NAME
> ----------
> Anna
> Ben
> Carl
> 3 rows selected
> ij> SELECT DISTINCT(name) FROM (SELECT name FROM names) AS n;
> NAME
> ----------
> Anna
> Ben
> Carl
> 3 rows selected
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