Form of UCD-based queries
Yuji SHIRASAKI
yuji.shirasaki at nao.ac.jp
Wed Jun 1 18:18:00 PDT 2005
Sorry, it was my misunderstanding.
see the following URL:
http://help.sap.com/saphelp_nw04/helpdata/en/ea/6af9455a5d48bd9ff9d9c5e26e32d9/content.htm
I tested on PostgreSQL that "ra" and ra are interpreted as the same
column. On the other hand, "RA" and ra is interpreted as different
column. So the delimited identifier is case sensitive and regular
identifier is treated as a lower-case letter on PostgreSQL.
But according to the SQL standard, regular identifier should be
treated as a upper-case letter.
Yuji SHIRASAKI
From: "Tony Linde" <Tony.Linde at leicester.ac.uk>
Subject: RE: Form of UCD-based queries
Date: Wed, 1 Jun 2005 17:18:25 +0100
> > In addition, "x" does not represent a column called x but a
> > column called "x". A double quate is a part of the column name.
>
> Really? That doesn't make sense at all. So you would have to have created
> your columns with double quotes around the names? I didn't think a database
> would allow that.
>
> Or am I misunderstanding you?
>
> T.
>
> > -----Original Message-----
> > From: Yuji SHIRASAKI [mailto:yuji.shirasaki at nao.ac.jp]
> > Sent: 01 June 2005 16:35
> > To: womullan at skysrv.pha.jhu.edu
> > Cc: Tony.Linde at leicester.ac.uk; voql at ivoa.net
> > Subject: Re: Form of UCD-based queries
> >
> >
> > From: "Wil O'Mullane" <womullan at skysrv.pha.jhu.edu>
> > Subject: Re: Form of UCD-based queries
> > Date: Wed, 1 Jun 2005 10:42:34 -0400
> >
> > > There may be a way but in most SQLs if you do
> > >
> > > select 'x' from tab
> > >
> > > you get
> > > 'x' back
> > > not a a colum called x
> >
> > That is because a single quate is used to express a string
> > constant, on the other hand a double quate is used to
> > expression delimited identifier.
> >
> > In addition, "x" does not represent a column called x but a
> > column called "x". A double quate is a part of the column name.
> >
> > > I just tried this on sql server created a function which returns a
> > > string and the did select dbo.ucd() from ABELL
> > >
> > > i get back
> > > Column1
> > > RA
> > > RA
> > > RA
> > > RA
> > > :
> > >
> > > not the values of the ra column
> >
> > ucd('ucd_expression') is a function not only of a string
> > 'ucd_expression'
> > but also of all the column values, so this is actually an
> > abbreviation of
> >
> > ucd('ucd_expression', column1, column2, column3, ...)
> >
> > Yuji SHIRASAKI
> >
> > > On Wed, Jun 01, 2005 at 03:23:40PM +0100, Tony Linde wrote:
> > > > Hi Yuji,
> > > >
> > > > > To avoid this confusion, why don't we use just a
> > function calling
> > > > > like ucd('pos.eq;src') ?
> > > >
> > > > I'd thought of that at first but figured it would confuse
> > the issue.
> > > >
> > > > But thinking on't further, it might actually fit. We could define
> > > > that the function ucd(_string_) should simply be resolved by the
> > > > end-point of the ADQL query into the unique column
> > identified by the
> > > > UCD '_string_' or the column which best fit that UCD if
> > it was multiply defined.
> > > >
> > > > We ought to go on to define guidelines for inclusion of
> > appropriate
> > > > metadata in the returned results so that end-users or (more
> > > > importantly) downstream applications can manipulate
> > multiple sets of results in a meaningful way.
> > > >
> > > > So no changes to ordinary parsers is required - if the end-point
> > > > does not understand the ucd() function, it'll treat it as
> > undefined.
> > > > And not much change to the spec is required except to
> > indicate that
> > > > this is a special function and what to do about it. (Tho' I'm not
> > > > suggesting it go into the v1.0 spec but we could have a 1.01 WD
> > > > released soon after the 1.0REC.)
> > > >
> > > > What do others think?
> > > >
> > > > Cheers,
> > > > Tony.
> > > >
> > > > > -----Original Message-----
> > > > > From: Yuji SHIRASAKI [mailto:yuji.shirasaki at nao.ac.jp]
> > > > > Sent: 01 June 2005 14:43
> > > > > To: Tony.Linde at leicester.ac.uk
> > > > > Cc: voql at ivoa.net
> > > > > Subject: Re: Form of UCD-based queries
> > > > >
> > > > >
> > > > > Also in sql99, double quotes are used for non-simple names.
> > > > >
> > > > > I found, however, that "double colons" is already used in
> > > > > SQL99 to describe the static method calling.
> > > > >
> > > > > For an example, ucd::"pos.eq;src" means the execution of a
> > > > > static method "pos.eq;src" of data class ucd.
> > > > >
> > > > > To avoid this confusion, why don't we use just a
> > function calling
> > > > > like ucd('pos.eq;src') ?
> > > > >
> > > > > At the moment, we don't define what value should be returned by
> > > > > this function, This will be defined in the next version of ADQL
> > > > > spec.
> > > > >
> > > > > ---
> > > > > Yuji SHIRASAKI
> > > > >
> > > > > From: "Tony Linde" <Tony.Linde at leicester.ac.uk>
> > > > > Subject: RE: Form of UCD-based queries
> > > > > Date: Wed, 1 Jun 2005 11:00:26 +0100
> > > > >
> > > > > > > In the SQL92 specification, double quotes are used for
> > > > > > > non-simple names.
> > > > > >
> > > > > > If it is the same in sql99, I'll buy it (I don't _like_ it:
> > > > > > double quotes indicate a string constant to me, same as single
> > > > > quotes, but if
> > > > > > it is the standard then we ought to adopt it).
> > > > > >
> > > > > > So, Yuji, an example of your proposal for UCD naming
> > would then
> > > > > > be ucd::"pos.eq;src" - yes?
> > > > > >
> > > > > > (BTW - why did the group settle on [] in the first place? And
> > > > > > will there be ructions if we change now? Still,
> > that's what the
> > > > > RFC period
> > > > > > is about, I
> > > > > > guess.)
> > > > > >
> > > > > > T.
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Yuji SHIRASAKI [mailto:yuji.shirasaki at nao.ac.jp]
> > > > > > > Sent: 01 June 2005 09:31
> > > > > > > To: Tony.Linde at leicester.ac.uk
> > > > > > > Cc: voql at ivoa.net
> > > > > > > Subject: Re: Form of UCD-based queries
> > > > > > >
> > > > > > >
> > > > > > > Hi, Tony
> > > > > > >
> > > > > > > From: "Tony Linde" <Tony.Linde at leicester.ac.uk>
> > > > > > > Subject: RE: Form of UCD-based queries
> > > > > > > Date: Wed, 1 Jun 2005 08:23:19 +0100
> > > > > > >
> > > > > > > > Interesting. Wonder what MS will do - they use [] for
> > > > > > > non-simple names
> > > > > > > > I seem to recall. Is there anything in sql-99
> > which allows
> > > > > > > > for handling non-simple names?
> > > > > > >
> > > > > > > In the SQL92 specification, double quotes are used for
> > > > > > > non-simple names.
> > > > > > >
> > > > > > > I found it in the following URL:
> > > > > > >
> > > > > > >
> > > > > > >
> > http://incubator.apache.org/derby/docs/ref/crefsqlj1003454.htm
> > > > > > > l
> > > > > > >
> > > > > > > It looks like ([]) is only used on the SQL Server as an
> > > > > > > optional functionality, and in a default setting
> > (") is used.
> > > > > > >
> > > > > > > MySQL uses back ticks (`) as a default, but when it
> > > > > running in ANSI
> > > > > > > double quotes (") will also work.
> > > > > > >
> > > > > > >
> > > > > > >
> > http://www.ispirer.com/doc/sqlways38/Output/SQLWays-1-034.html
> > > > > > >
> > > > > > > So, I support to use (") for non-simple names based on the
> > > > > > > SQL92 specification.
> > > > > > >
> > > > > > > Yuji SHIRASAKI
> > > > > > >
> > > > > > > > I guess it isn't an issue in the parser since [ where you
> > > > > > > > are expecting a name will indicate the start of a
> > non-simple
> > > > > > > name while [
> > > > > > > > after you've got the whole name will indicate the start of
> > > > > > > an array.
> > > > > > > > Parsing is all context-based anyway.
> > > > > > > >
> > > > > > > > I still like the [ but am not overly bothered if someone
> > > > > > > can suggest a
> > > > > > > > workable alternative.
> > > > > > > >
> > > > > > > > T.
> > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: owner-voql at eso.org [mailto:owner-voql at eso.org]
> > > > > On Behalf
> > > > > > > > > Of Yuji SHIRASAKI
> > > > > > > > > Sent: 01 June 2005 06:27
> > > > > > > > > To: voql at ivoa.net
> > > > > > > > > Subject: Re: Form of UCD-based queries
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > BTW, I noticed that "[]" is used to express an array
> > > > > data type
> > > > > > > > > in SQL99.
> > > > > > > > >
> > > > > > > > > e.g. select column_name[0], column_name[1], ...
> > > > > > > > >
> > > > > > > > > If we have a plan to incorporate the SQL99 syntax in the
> > > > > > > future, it
> > > > > > > > > might be better to find another way to express
> > > > > non-simple names.
> > > > > > > > >
> > > > > > > > > ---
> > > > > > > > > Yuji SHIRASAKI, Research Fellow
> > > > > +81-422-34-3579 (tel)
> > > > > > > > > National Astronomical Observatory of Japan
> > > > > +81-422-34-3840 (fax)
> > > > > > > > > Osawa, Mitaka, Tokyo, Japan
> > > > > > > yuji.shirasaki at nao.ac.jp
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > From: Yuji SHIRASAKI <yuji.shirasaki at nao.ac.jp>
> > > > > > > > > Subject: Re: Form of UCD-based queries
> > > > > > > > > Date: Wed, 01 Jun 2005 09:28:12 +0900 (JST)
> > > > > > > > > Message-ID: <20050601.092812.43003048.Yuji
> > > > > SHIRASAKI at nao.ac.jp>
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > From: "Tony Linde" <Tony.Linde at leicester.ac.uk>
> > > > > > > > > > Subject: RE: Form of UCD-based queries
> > > > > > > > > > Date: Tue, 31 May 2005 17:06:00 +0100
> > > > > > > > > > Message-ID:
> > > > > > > > > > <200505311606.BAA01951 at mail-hub.mtk.nao.ac.jp>
> > > > > > > > > >
> > > > > > > > > > > > Is it necessary to use [] ?
> > > > > > > > > > > > I think it is possible to allow arbitrary string
> > > > > > > after "ucd::"
> > > > > > > > > > > > keyword.
> > > > > > > > > > >
> > > > > > > > > > > Not sure if it is necessary but since we've
> > got the []
> > > > > > > > > > > to
> > > > > > > > > allow the
> > > > > > > > > > > handling of non-simple names, it seems to
> > fit. Does it
> > > > > > > > > cause a problem?
> > > > > > > > > >
> > > > > > > > > > It is possible for a SQL parser to recognise the
> > > > > > > expression such
> > > > > > > > > > as "[ucd::pos.eq;src]" as a column name
> > > > > "ucd::pos.eq;src", so
> > > > > > > > > I suggeset
> > > > > > > > > > to use an expression like "ucd::[pos.eq;src]",
> > > > > where "ucd::"
> > > > > > > > > > is out side of the bracket.
> > > > > > > > > >
> > > > > > > > > > ---
> > > > > > > > > > Yuji SHIRASAKI, Research Fellow
> > > > > > > +81-422-34-3579 (tel)
> > > > > > > > > > National Astronomical Observatory of Japan
> > > > > > > +81-422-34-3840 (fax)
> > > > > > > > > > Osawa, Mitaka, Tokyo, Japan
> > > > > > > yuji.shirasaki at nao.ac.jp
> > > > > > > > > >
> > > > > > > > >
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