It's getting curiousor and curiousor...
Using the TBC SPARQL tab, when I call a function that filters according
to an argument, e.g.:
SELECT ?user
WHERE {
?project ModelManagement:hasUser ?user .
?user Common:name ?username .
FILTER (?username = ?arg1) .
}
As long as I pass in an argument that has a match:
SELECT ?value
WHERE {LET(?user := ModelManagement:getProjectUser("john"))
?user ModelManagement:firstName ?value}
the function returns just one result as expected (in this case for some
reason the blank result rows aren't returned). However, if I pass in a
value that has NO matches:
SELECT ?value
WHERE {LET(?user := ModelManagement:getProjectUser("xxx"))
?user ModelManagement:firstName ?value}
It acts like the FILTER statement isn't there, and all User's names in
the model are returned. I would have expected no results to be
returned. Btw, I'm seeing this same behavior in my code too. Am I
thinking about this wrong, or is there perhaps a problem with how FILTER
works within a Function?
Jeff
> -----Original Message-----
> From: Schmitz, Jeffrey A
> Sent: Wednesday, May 27, 2009 1:15 PM
> To: [email protected]
> Subject: [tbc-users] Re: [SPIN] Using FILTER with function arguments
>
> On a related note...
>
> "(or at least not return the result as a valid binding)."
>
> It's interesting that the number of rows returned from such a
> query in TBC (and I assume in the code) seems to be based on
> what would be returned if the FILTER statement wasn't there,
> even if the rows end up having no bindings. In the attached
> screenshot, there are 4 rectangles in the model being
> queried, only one of which is a square. Note the three empty
> result rows returned. So the variable returned from a
> function call acts as an OPTIONAL binding by default (the
> opposite of regular variables). And I never thought there'd
> be any reason to use FILTER (bound(?x)), but now there is.
> If you want the function to actually filter (something I was
> hoping to right a lot of functions to precisely do), you
> should be able to do something like:
>
> SELECT ?value
> WHERE {
> ?rec spinsquare:width ?width .
> ?rec spinsquare:height ?height .
> LET (?value := SpinLib:twoDimArea(?width, ?height)) .
> FILTER(bound(?value))
> }
>
> No?
>
> Jeff
>
>
>
>
>
>
>
> > -----Original Message-----
> > From: Holger Knublauch [mailto:[email protected]]
> > Sent: Wednesday, May 27, 2009 12:37 PM
> > To: [email protected]
> > Subject: [tbc-users] Re: [SPIN] Using FILTER with function arguments
> >
> >
> > Hi Jeff,
> >
> > I can't see how this is limited to SPIN - the same should
> happen with
> > any other function. Could you try to put something else
> into the LET
> > clause? The ARQ engine should simply never call the LET after the
> > FILTER (or at least not return the result as a valid binding).
> >
> > Holger
> >
> >
> > On May 27, 2009, at 10:23 AM, Schmitz, Jeffrey A wrote:
> >
> > >
> > > Hello,
> > > I'm having trouble when using SPIN function arguments within a
> > > FILTER statement. E.g. using the spinsquare model I
> > initially added a
> > > simple twoDimArea function that seems to work correctly:
> > >
> > > SELECT ?result
> > > WHERE {
> > > LET (?result := (?arg1 * ?arg2)) .
> > > }
> > >
> > > When I call it with something like:
> > >
> > > SELECT ?value
> > > WHERE {
> > > ?rec spinsquare:width ?width .
> > > ?rec spinsquare:height ?height .
> > > LET (?value := SpinLib:twoDimArea(?width, ?height)) }
> > >
> > > the correct values are returned based on what's in the model.
> > > However,
> > > if I change the function query to filter out everything except
> > > squares:
> > >
> > > SELECT ?result
> > > WHERE {
> > > FILTER (?arg1 = ?arg2) .
> > > LET (?result := (?arg1 * ?arg2)) .
> > > }
> > >
> > > The filtering doesn't happen, I still get all the results.
> > I've tried
> > > other variations of FILTER statements that uses only one
> > argument and
> > > none of them seem to do any filtering. Should FILTER statements
> > > within SPIN Functions work?
> > >
> > > Thanks,
> > > Jeff
> > >
> > > >
> >
> >
> > >
> >
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"TopBraid Composer Users" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/topbraid-composer-users?hl=en
-~----------~----~----~----~------~----~------~--~---
