Alexandr Savinov wrote:
> Jon Heggland schrieb:
>
>> In article <1132798608.160942.270970_at_o13g2000cwo.googlegroups.com>,
>> michael_at_preece.net says...
>>
>>> If you have a text/string field and it can have an empty string what
>>> have you got? What is the value of the data? How does that value differ
>>> from "no value at all"? Question mark.
>>
>>
>>
>> Are two variables/"fields" (of the same type) with "no value at all"
>> equal?
>
>
> The question does not make sense because we cannot talking about things
> that do not exist. In particular, it does not make sense to ask if two
> things that do not exist are equal or not.
Yet it is a syntactically correct question to ask in any query language.
Let me rephrase: while it is true that it makes no sense, there is
no formal reason why it shouldn't.
Received on Thu Nov 24 2005 - 17:47:24 CST
