Re: Nulls get converted to 0 problem

From: Dmitry Tkach <dmitry(at)openratings(dot)com>
To: Jon Earle <je_pgsql(at)kronos(dot)honk(dot)org>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Nulls get converted to 0 problem
Date: 2003-06-06 14:53:25
Message-ID: 3EE0AAE5.8090808@openratings.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

>
>
>If you're testing a value, you're testing to see if there's something in
>there or not - what difference does it make if the variable contains 0, ""
>or NULL?
>
>
World of difference :-)
An intereger value of 0 is *certainly* "somethign", as well as an empty
string.

>Why not adhere to the practices inherent (and thus anticipated by
>developers) in other languages (C comes to mind) where 0, NULL and "" are
>equivalent?
>
Not at all. An empty string in C is a valid pointer to a memory
location, that contains a 0, and NULL is a pointer to a memory location
that does not exist.
They are not equivalent at all.

Dima

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Henrik Steffen 2003-06-06 15:03:38 update phenomenon
Previous Message Stephan Szabo 2003-06-06 14:47:34 Re: Create index on the year of a date column