ADQL v0.7.3

[Tony Linde]

Yes, I got caught out many years ago in the same manner.

> I found it _very_ hard to discover this in the Postgres 
> manual, and in the SQL92 standard.

So, does the SQL-92 standard mandate right to left interpretation?

Cheers,
Tony. 

> -----Original Message-----
> From: owner-voql at eso.org [mailto:owner-voql at eso.org] On 
> Behalf Of Clive Page
> Sent: 02 March 2004 09:08
> To: voql at ivoa.net
> Subject: RE: ADQL v0.7.3
> 
> On Tue, 2 Mar 2004, Tony Linde wrote:
> 
> > The statement
> >   a / b / c / d
> > is perfectly valid. It is up to the interpreter what is 
> done with it.
> 
> I had been keeping my head down, but this makes me want to 
> say that it is vital that we get this right, or at least make 
> it clear what the right interpretation is.
> 
> Recently I got caught when translating some code from 
> Fortran90 code into pl/pgSQL for Postgres (to implement 
> HEALPix indexing).  The expression "a / b / c"
> has a clear Fortran interpretation of
> "(a/b)/c"
> but I discovered by getting wrong answers that in Postgres's 
> version of SQL at least it is interpreted as "a/(b/c)".
> I found it _very_ hard to discover this in the Postgres 
> manual, and in the SQL92 standard.
> 
> 
> --
> Clive Page
> Dept of Physics & Astronomy,
> University of Leicester,    Tel +44 116 252 3551
> Leicester, LE1 7RH,  U.K.   Fax +44 116 252 3311
>