Re: Appending null produces null?

On Thu, 9 Nov 2000, Jeff Eckermann wrote:

> extracts=# select bill_address1, bill_address2, bill_address1 || ' ' ||
> bill_address2 from customers where external_id = 20037514;
>   bill_address1  | bill_address2 | ?column?
> -----------------+---------------+----------
>  6745 Avalon Ave |               |
> (1 row)
>
> I know that the usual operations with 'null' will produce null, but I didn't
> expect it in the case of a text field being appended to another text field.
> No doubt that follows as a matter of strict principle, but the outcome makes
> no sense from a purely practical point of view.  Is this really the intended
> behaviour?  I know that I can work around this with a 'coalesce' or
> something similar, but that seems unnecessarily messy.
Yes, this is really the intended behavior. Null means 'no value known',
which is different from empty string...