Hello
2011/12/8 Ingmar Brouns <swingi@gmail.com>:
>
> Hi,
>
> The documentation of the function concat states: Concatenate all arguments.
> NULL arguments are ignored.
> Intuitively I would expect that
>
> concat(NULL, NULL) IS NULL
>
> but this is not the case as it equals the empty string. As no empty string
> was passed, the empty string seems
> to come from nowhere. I found this behavior not immediately clear from the
> documentation..
>
yes - it returns empty string - concat is "barier" to nulls
it should be better documented
Regards
Pavel Stehule
> Kind regards,
>
> Ingmar Brouns
>
>
>