POV-Ray : Newsgroups : povray.off-topic : Programming langauges : Re: Programming langauges Server Time
5 Sep 2024 07:25:17 EDT (-0400)
  Re: Programming langauges  
From: Captain Jack
Date: 27 Oct 2009 16:56:42
Message: <4ae75e8a$1@news.povray.org>
"Darren New" <dne### [at] sanrrcom> wrote in message 
news:4ae75bb2$1@news.povray.org...
> Outer joins are peversities caused by people not normalizing columns that 
> can have NULL in them. If none of your tables can have a NULL, you never 
> need an outer join.

Hmm... I use outer joins for optional data a lot, without respect to nulls. 
Like this:

SELECT C.Name, U.UserName
FROM tblClients AS C
OUTER JOIN tblUsers AS U ON U.UserId = C.LastEditUserID

In that case, the column LastEditUserID is zero (another way of logically 
saying Null, I s'pose) when the client row is new and has never been edited. 
I do that so that in that query I always get the client data, with the user 
name being optional.

I'll be the first to admit that DB management is not my strong suit, though.


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