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From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-4) "order by" is not supported for "insert ... select"
Date Sat, 19 May 2007 12:36:16 GMT

    [ https://issues.apache.org/jira/browse/DERBY-4?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12497149
] 

Knut Anders Hatlen commented on DERBY-4:
----------------------------------------

If the temp1 table mentioned in the description had a unique constraint on s, and temp2.i
were declared as generated by default as identity (instead of always as identity), the following
query would be pretty close to what you want:

insert into temp2 select count(b.s), a.s from temp1 a, temp1 b where b.s <= a.s group by
a.s

It's not a perfect match, but it would at least give the identity column the same ordering
as the s column. Some extra tweaking is needed if temp2 is not empty when the insert is executed.

> "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
>         Attachments: insertOrderBy.diff
>
>
> 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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