NULL vs. None and MySQLdb

Aahz Maruch aahz at panix.com
Tue Sep 19 18:05:12 CEST 2000


[BTW, if you're going to cc my e-mail account, please say so.]

In article <31575A892FF6D1118F5800600846864D5B10FB at intrepid>,
Simon Brunning  <SBrunning at trisystems.co.uk> wrote:
> From:	aahz at panix.com [SMTP:aahz at panix.com]
>>
>> None is the Python equivalent of NULL; what's wrong with None?
> 
>None is not the same as NULL.

I didn't say it was the same, I said it was equivalent.

>None == None, but NULL <> NULL. For a numeric field, None == 0, but NULL <>
>0. NULL doesn't equal *anything* - it means not applicable, unknown, or
>suchlike. (I recommend SQL for Smarties by Joe Celko for a full discussion
>of this.)
>
>Python doesn't have any equivalent, AFAIK. Which is a shame - a native NULL
>would be *very* useful for DB work.

You should be using the "is" operator in Python to operate on None, just
the way you do in SQL.  Python has different semantics from SQL for the
relational operators, but you can get to equivalences fairly easily.
-- 
                      --- Aahz (Copyright 2000 by aahz at pobox.com)

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