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From Army <qoz...@sbcglobal.net>
Subject Re: [jira] Commented: (DERBY-147) ERROR 42X79 not consistant ? - same column name specified twice
Date Mon, 28 Feb 2005 22:28:20 GMT

> Hi,
> 
> Don't know why the system was coded to throw exception for duplicate
> columns but it seems like it has been around in Cloudscape from very
> beginning.

I only looked at this briefly, so please don't take this as the final word or anything--but
here's one reason why we 
might want to throw an error:

// This is fine.
ij> select i, (i * -1) as i from t1;
I          |I
-----------------------
2          |-2
4          |-4
8          |-8

// But this...???
ij> select i, (i * -1) as i from t1 ORDER BY i;

Which column is the result set going to be ordered by?  Is it better to just pick one and
go with it, or is it better to 
throw a duplicate column exception?

Just a thought,
Army


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