Re: NULL != text ?

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От Michael Glaesemann
Тема Re: NULL != text ?
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Msg-id 671666AF-2054-4CF6-837D-83E23C2C1FB3@myrealbox.com
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Ответ на Re: NULL != text ?  (Michael Fuhr <mike@fuhr.org>)
Список pgsql-general
On Oct 20, 2005, at 23:45 , Michael Fuhr wrote:

> On Thu, Oct 20, 2005 at 03:57:41PM +0900, Michael Glaesemann wrote:
>
>> On Oct 20, 2005, at 15:44 , Michael Fuhr wrote:
>>
>>>  expression IS DISTINCT FROM expression
>>>
>>>  For non-null inputs this is the same as the <> operator.  However,
>>>  when both inputs are null it will return false, and when just one
>>>  input is null it will return true.  Thus it effectively acts as
>>>  though null were a normal data value, rather than "unknown".
>>>
>>
>> Interesting! Thanks, Michael. You don't happen to know off the top of
>> your head if that's standard SQL, do you?
>>
>
> IS DISTINCT FROM is defined in SQL:1999 and SQL:2003.

Thanks!

Michael Glaesemann
grzm myrealbox com




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