Brent Dombrowski wrote:
> Lonni J Friedman wrote:
>> I've got a Postgresql-8.4.x instance with a bunch of tables taht have
>> a text column (called 'active') that can contain any one of the
>> following values:
>> <some other text string>
>> When I run the following query, it seems to ignore NULL values:
>> SELECT * FROM mytbl WHERE active!='disabled'
>> and only returns rows where active!='disabled' AND active IS NOT NULL.
>> Is postgresql implicitly assuming that I want non-NULL values?
>> I can provide additional information, if requested.
> Unfortunately, there is only one NULL and it can take on several meanings.
> Because of this, most databases will not perform comparison operations on NULL.
> NULL is not comparable to anything, including itself.
> NULL == NULL will return FALSE on most systems.
"Most" databases? "Most" systems?
*ALL* SQL-compliant products.
Honi soit qui mal y pense.
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