[jira] [Commented] (DERBY-6983) Support SELECT * for IN predicate subqueries when it is "obvious" that the asterisk expands to exactly one column

["Rick Hillegas (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DERBY-6983?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16376777#comment-16376777 ] 

Rick Hillegas commented on DERBY-6983:
--------------------------------------

Thanks for logging this bug, Lukas. It is the inner * which bothers Derby. The following query also fails:

{noformat}
SELECT tablename
FROM sys.systables
WHERE tablename IN (
  SELECT *
  FROM (
    SELECT 'SYSTABLES' t
    FROM sysibm.sysdummy1
  ) t
)
;
{noformat}

The following workaround works for me:

{noformat}
SELECT *
FROM sys.systables
WHERE tablename IN (
  SELECT t
  FROM (
    SELECT 'SYSTABLES' t
    FROM sysibm.sysdummy1
  ) t
)
;
{noformat}


> Support SELECT * for IN predicate subqueries when it is "obvious" that the asterisk expands to exactly one column
> -----------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-6983
>                 URL: https://issues.apache.org/jira/browse/DERBY-6983
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.14.1.0
>            Reporter: Lukas Eder
>            Priority: Major
>
> The following query is not allowed in Derby:
> {code:java}
> SELECT *
> FROM sys.systables
> WHERE tablename IN (
>   SELECT *
>   FROM (
>     SELECT 'SYSTABLES' t
>     FROM sysibm.sysdummy1
>   ) t
> ){code}
> The error I'm getting is:
> {code:java}
> 'SELECT *' only allowed in EXISTS and NOT EXISTS subqueries.{code}
> In this case, it is "obvious" that the asterisk (also a qualified asterisk: t.*) expands to exactly one column and the query should be perfectly fine. I'm not aware of any other databases with such a restriction.
>  



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)