From: Noel Winstanley <Noel.Winstanley-at-manchester.ac.uk>
Subject: 'AS' - ADQL WD v1.05
Date: Tue, 4 Jul 2006 01:04:06 +0200
> I notice that alhough table aliases are required, it is optional
> whether the 'AS' keyword is used to denote this. I'd argue that
> having optional syntax doesn't help implementors, and is just
> confusing to users. Furthermore, I don't think the statement on page 4
> "ADQL/s and ADQL/x are translatable to each other without loss of
> information"
Since the 'AS' keyword does not have any information, this statement is true even if the 'AS' keyword is dropped out between the translations.
'AS' keyword is just introudced for compatibility with the standard SQL.
The rolse of the 'AS' keyword is just to clearly seprate the table name and alias name. There is no semantic role for this. Allowing to use the 'AS' keyword is just for convinience for an SQL master.
Yuji Shirasaki.
> is possible, considering optional syntax, unless the adql/x version
> has a way of recording which optional fragments of syntax have been
> used (and I really hope this isn't the case).
>
> so I'd say choose one, either one, but don't include both.
>
> same applies to column aliases too.
>
> ---
> http://wiki.astrogrid.org/bin/view/Main/NoelWinstanley
> Senior Java Developer, AstroGrid Project
> Jodrell Bank Observatory, University of Manchester
>
>
>
Received on 2006-07-04Z09:30:34