[Zope] sql method attributes

Hello, I read some place that a ZSQL method can get attributes from two places: variables and through HTTP. If I use something like method?argv=argv it works fine. But I also have argv defined as a property. For some reason the method doesn't recognise this. Is my understanding of how ZSQL methods are supposed to work flawed? In other words how can I pass an argument to a ZSQL method without having to include it in a URL or a form. Thanks, -Joseph Kocherhans