Dieter Fischer (grid-it) wrote:
> Hello
>
>
>>SELECT 'abc'::text || null::text;
>>
>>The last example looks like a bug,
>>but if it is intentionally so, its
>>at least very annoying and inconvenient.
>
>
> NULL means here UNKOWN. You cannot add or concatenate something to an
> undefined Value.
You can but the result is UNKNOWN.
Regards
Gaetano Mendola