Boyd, Todd M. wrote:
-----Original Message-----
From: Chris [mailto:dmagick@xxxxxxxxx]
Sent: Tuesday, January 27, 2009 4:04 PM
To: Boyd, Todd M.
Cc: php-general@xxxxxxxxxxxxx
Subject: Re: Global Changes With Loop To Allow Nulls In A
Table...
The other responses should get you started if this is something you
really want to do. However, I'll play devil's advocate here and just
raise the question why you would want to make this change in the
first
place. I'm not quite as anti-NULL as a lot of arguments I've read
against them, but I tend to agree that the number of columns that
accept NULL values should be kept as small as possible. Even if you
decide that you need to allow NULL values in some cases, IMHO I
wouldn't write a script that ran through my entire database and
opened
every column in every table to accept.
I just thought I'd throw this out there...
A lot of people who post questions on this list are programming their
algorithms and structuring their applications in a certain way because
that's what the client wants, or that's what their boss told them to
do. Yes, accepting NULL values in a database is frowned upon (unless
the table is a transaction table)... but I doubt his boss or his client
cares in the least.
I don't understand what you mean about a "transaction table" - you
should only use nulls if you understand what they do and why you'd need
them in that particular case. I'd ask why and find specifically what
they want/why they suggested it and make sure they understand the
repercussions.
A transaction table -- a table that is used to house the state of a transaction. If the transaction is incomplete, some of its values will be NULL. This is, of course, only one method for employing a transaction system. There exist others that use many disparate tables for separate steps in the transaction, but I've seen several that use one table with NULL columns for steps that haven't yet been processed.
Ah like a queue processing table? I understand what you mean now :)
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