[
https://issues.apache.org/jira/browse/DERBY-6008?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13526374#comment-13526374
]
Dag H. Wanvik edited comment on DERBY-6008 at 12/7/12 1:22 PM:
---------------------------------------------------------------
Thanks, Knut. I agree the intersect looks wrong indeed. As for the anomaly in
values 1 order by 1+2, I guess this is because the logic to analyze the order
by in this case resides in RowResultSetNode, not in UnionNode/SetOperatorNode
as in the multi-valued case. I'd guess an omission since it's a corner case.
And yes, I could remove the special case for removeOrderByColumns, probably,
and just add a comment to remind the reader of the fact. I added it
first because I thought I had an error requiring it, but that turned to be
something else, but I kept it mostly as a documentary thing.
was (Author: dagw):
Thanks, Knut. I agree the intersect looks wrong indeed. As for the anomaly
in values 1 order by 1+2, I guess this is because the logic to analyze the
order by in this case resides in RowResultSetNode, not in
UnionNode/SetOperatorNode as in the multi-valued case. I'd guess an omission
since it's a corner case.
> Allow ORDER BY and FETCH/OFFSET in set operands
> -----------------------------------------------
>
> Key: DERBY-6008
> URL: https://issues.apache.org/jira/browse/DERBY-6008
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Reporter: Dag H. Wanvik
> Assignee: Dag H. Wanvik
> Attachments: derby-6008-a.diff, derby-6008-a.stat, derby-6008-b.diff,
> derby-6008-b.stat, derby-6008-c.diff, derby-6008-c.stat
>
>
> Currently, Derby doesn't allow ORDER BY nested in a set operand, e.g. in the
> following construct:
> (select i from t1 order by j offset 1 row) union
> (select i from t2 order by j desc offset 2 rows)
> This is allowed by the standard, as far as I can understand, cf. this quote
> from section 7.12 in SQL 2011:
> <query expression body> ::=
> <query term>
> | <query expression body> UNION [ ALL | DISTINCT ]
> [ <corresponding spec> ] <query term>
> | <query expression body> EXCEPT [ ALL | DISTINCT ]
> [ <corresponding spec> ] <query term>
> <query term> ::=
> <query primary>
> | <query term> INTERSECT [ ALL | DISTINCT ]
> [ <corresponding spec> ] <query primary>
> <query primary> ::=
> <simple table>
> | <left paren> <query expression body>
> [ <order by clause> ] [ <result offset clause> ] [ <fetch first clause>
> ] <right paren>
> I.e. the left paren chooses the second alternative in the production for
> <query primary>.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
