[Zope] SQL Methods and namespace question

[Rik Hoekstra]

Ulrich Wisser wrote:
> 
> Hi Rik,
> 
> > Perhaps I could help you a bit with your question
> >
> > > I tried an argument arg:int=0 and in SQL
> >
> > Where did you put the arg:int=0? I can't think of a place where this would
> > be valid as such.
> > What is your intention with this method?
> 
> in the argument list of the ZSQL method. So the
> method should import arg from REQUEST and if
> there isn't any "arg" value in the Request arg
> should be set to 0.


> 
> > > SELECT * FROM DATA
> > > <dtml-sqlgroup where>
> > >   <dtml-if arg>

If you want to exclude arg if it is 0 this tag should read

<dtml-if "arg and arg<>0">

if you want to leave arg unset, just don't pass it to you SQL method
(either in your form or otherwise)

> > >     <dtm-sqltest arg type=int>

according to the sql documentation sqltest is used for testing against
sql values not against variables in the current namespace, though I've
neve used it myself, so I may be mistaken (the documentation is not
overly clear)

> > >   </dtml-if>
> > > </dtml-sqlgroup>
> > >
> > > and I always get
> > >
> > > SELECT * FROM DATA WHERE ARG=0
> > >
> > > Shouldn't that be impossible?
> >
> > Not per se.
> 
> When arg is 0, how can <dtm-if arg> evaluate
> it to true?

Because there is a variable arg and its value is 0 ;-)
0 does not mean false in DTML or Python.

Does this make it clearer?

Rik