CONCAT and NULLs

[Ruslan Zasukhin]

On 5/30/08 6:03 PM, "william humphrey" <shoreagent at gmail.com> wrote:

Hi William,

> Tell me when you concate using  || ' ' ||  in valentina it evaluates nulls as
> string ( in other words when it is "a"  || ' ' ||  NULL  || ' ' ||  "b"  --
> the result is ab but when I did NULL  || ' ' || 'a'  || ' ' ||  NULL  || ' '
> ||  'b' the result was NULL in Oracle the result would be string but in MySQL
> the result would always be NULL. If in Valentina the result is supposed to
> always be NULL then maybe the field that I think is NULL actually isn't. Is
> Valentina the same as MySQL for this or Oracle or something different?
> 
> I would like it to return string as evaluating to NULL just because there is
> one NULL seems to me not a good feature.

I will ask Ivan comment on this.

But in general rule of SQL Standard is:

    if AT LEAST one parameter of a function is NULL
    then result also is NULL.

Agree this is quite logical rule.


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]