Re: Error Code XQ0058

Panagiotis Reveliotis wrote:

> In "XQuery 1.0: An XML Query Language" / F Summary of Error Conditions (Non-Normative),
> it is stated that:
> 
> err:XQ0058
> 
>     It is a static error if multiple schema imports specify the same target namespace.
> 
> I am wondering why is this considered an error, given that XML Schema allows for more than
> one schema files to have the same targetNamespace. In fact, it allows for multiple schemas
> sharing the same targetNamespace to be combined using the include mechanism. 

Hi Panagiotis,

First, I'm going to treat this as a question unless you tell me that you 
want to raise an issue on this subject.

Each XQuery implementation has its own way of locating schema documents. 
  A schema import tells the implementation to import the schema for a 
given target namespace - this schema may consist of any number of schema 
documents (which you refer to as 'schema file'). The schema that is 
imported includes all the schema documents the implementation finds for 
that namespace - so there's nothing left to import.

In this model, the schema location is only a hint, and schema import for 
  a given schema happens all at once. Multiple locations may be given as 
hints in a single import.

This is, of course, different from the approach taken in XML Schema and 
in several programming languages.

Is this clear? Do you have concerns about this approach?

Jonathan

Received on Saturday, 14 August 2004 16:50:40 UTC