Re: query-question

Stephan Szabo wrote:
> On Thu, 11 Sep 2003, [ISO-8859-1] Alexander Bl?m wrote:
>
>
>>hello,
>>
>>I'm facing an odd problem.
>>I have a query:
>>
>>SELECT "K?rzel", "Autor(en)", "Titel"
>>FROM "tblTitelangaben"
>>WHERE "Titel"||"K?rzel"||"Monographie-K?rzel"||"Autor(en)" ILIKE '%er%';
>>
>>this works like a charm.
>>
>>but if I add another ||"something" - which might be emtpy, I get no
>>results.. why?
>>
>>WHERE
>>"Titel"||"K?rzel"||"Monographie-K?rzel"||"Autor(en)"||"Herausgeber"
>>ILIKE '%er%';
>>
>>|| is the same as "OR", is it not?
>
>
> No, it's string concatenation. Also, remember that NULLs are special
> a || NULL is NULL.  You can use coalesce(field,"") to get an empty string
> if field is NULL.
>
>
>>1 OR 0 = 1
>>1 OR 1 = 1
>>0 OR 0 = 0
>>right?
>
>
> And even for OR, the above isn't true in SQL because of NULLs.
>   1 | 0 | N
> 1 1 | 1 | N
> 0 1 | 0 | N
> N N | N | N
>
>

THANK YOU VERY MUCH!!! ;))

that did the deed, exactly as intended!!
now I understand.

thanks again to all of you!

cheers,
    alex