Null and concat

[Thorsten Hohage]

Hi Bart,

On 2007-10-05, at 14:03, Bart Pietercil wrote:

> SELECT CONCAT('Va’, NULL, ‘na’);
>
> crashes VStudio

no - I got a "unexpected token NULL"

> SELECT CONCAT('Va’, NULL)
> I get unexpected token NULL.

same here and IMHO this is ok, because NOBODY would type a constant  
NULL in a concat statement.

BUT

when I do

select concat(name,'-',firstname,'-',company) from visitors where  
city like '%burg%'

and there is a row with name = null and firstname = null I would  
expect reading the wiki, that I'll get "NULL" as result, but I get "-- 
objectmanufactur" now while this is fine in many situations to handle  
NULL as an empty string in string operations, the wiki tells  
something different.

Furthermore I then expect that NULL are always handled as empty  
string in any string operation.



regards

Thorsten Hohage
--
objectmanufactur.com - Hamburg,Germany