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At 05:19 PM 7/6/2002 -0400, Mike Champion wrote:
>7/6/2002 4:25:02 PM, Jonathan Robie
> >And if you use the static typing, this error will not occur.
>If you use static typing throughout your organization, with a standard
>infrastructure so that the types mean exactly the same thing, and you
>impose the same on your entire supply chain and customer base, THEN
>this error will not occur. No disagreement from me!
>There would, however, be no need for XML in that environment :~)
Are you saying that XML is not needed in any environment where instances
are required to validate against a given schema?
Using static typing establishes that your query is safe as long as the data
validates. You don't have to require the rest of the organization to use
static typing - the static type check is just a way of ensuring that your
query is typesafe.
If the rest of the organization is giving you data that does not validate,
then you will not be able to use typesafe functions. You could still use
queries based on well-formed XML as long as you are quite certain that all
the schemas use an element called 'price' that contains the numbers you
woiuld want to sum. But you don't have a contract with your data producers
if you don't have validated data.
Incidentally, you can either parse their data against your schema, or
import their schema into the query. Either way, you can establish that the
query and the data match.
Why do you need XML in this environment? For all the traditional reasons:
- Exchanging information in open, easily parsed formats
- Validation - establishing a contract between data producers and consumers
- Crossing platform boundaries
- Crossing programming language boundaries
- XML messaging
I don't see why you don't need XML in this environment.