[Zope] "Missing" attribute with ZSQL methods?

[Stephane Bortzmeyer]

On Wednesday 17 January 2001, at 11 h 30, the keyboard of "Ron Bickers" 
<rbickers@logicetc.com> wrote:

> "missing" is only effective if the variable telephone cannot be found.  Even
> if it has a null or None value, it's not considered missing.  Try <dtml-var
> telephone null="(No phone)"> instead.

This one works fine (you got the reason right) and I missed it in the 
documentation.

Emmanuel Philippot <strasser@multimania.com> suggested another way, which 
seems to do the same:

<dtml-var telephone><dml-unless telephone>(No phone)</dtml-unless>

Thanks to both of you.