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From "Bernt M. Johnsen (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-4) "order by" is not supported for "insert ... select"
Date Wed, 16 May 2007 08:53:16 GMT

    [ https://issues.apache.org/jira/browse/DERBY-4?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12496230
] 

Bernt M. Johnsen commented on DERBY-4:
--------------------------------------

I do not agree that we should implement this "feature". First of all, it is not defined in
the standard, and secondly it makes no sense wrt. SQL as a language. SQL is basically a set
language where the rows have no order. The ORDER BY clause is used to order the rows when
they are retrieved *from* the database.

Although the following SQL:
INSERT INTO T VALUES(1);
INSERT INTO T VALUES(2);
SELECT * FROM T;

In most databases will give you the result
1
2
But I've seen otherwise, and that's completely compliant with the standard. I would say that
any application based on the assumption that the INSERT order has any influence on the result
from a SELECT statement withou an ORDER BY clause is buggy, so the tool Bryan is referring
to should be fixed.

-1 To this "feature".



> "order by" is not supported for "insert ... select"
> ---------------------------------------------------
>
>                 Key: DERBY-4
>                 URL: https://issues.apache.org/jira/browse/DERBY-4
>             Project: Derby
>          Issue Type: New Feature
>          Components: SQL
>            Reporter: Christian d'Heureuse
>         Assigned To: Bryan Pendleton
>            Priority: Minor
>
> When filling a table with "insert ... select ...", "order by" cannot be specified.
> There is not method to copy a table sorted into another table (except using export/import).
This would be useful to optimize performance for big tables, or to create identity values
that are ascending (related to another column).
> Example:
> create table temp1 (
>    s varchar(10));
> insert into temp1 values 'x','a','c','b','a';
> create table temp2 (
>    i integer not null
>       generated always as identity
>       primary key,
>    s varchar(10));
> insert into temp2 (s)
>    select s from temp1 order by s;
> --> Error: "order by" is not allowed.
> -- trying to use "group by" instead of "oder by":
> insert into temp2 (s)
>    select s from temp1 group by s;
> select * from temp2;
> --> "group by" did not sort the table.

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