
|
[oracle-l]
||
[Date Prev]
[08-2004 Date Index]
[Date Next]
||
[Thread Prev]
[08-2004 Thread Index]
[Thread Next]
RE: how to generate the output w/o using temp table
- From: "Lex de Haan" <lex.de.haan@xxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 2 Aug 2004 21:23:26 +0200
of course, I knew someone had to bring that up :-)
well, in short, they are the "enemies" ...
there has been a fierce academic battle in the ISO world between two "camps"
about this issue of temporal data. and since the ISO standardization process
is based upon achieving consensus, the idea of standardizing temporal data
was put on hold a while ago. it was supposed to become part 7 of the
SQL:2003 standard, but if you have access to the ANSI/ISO SQL standard (it
is not freely accessible, unfortunately) you will find out that part 7
simply doesn't exist -- there is a gap in the parts numbering.
If you really, really, really like this topic very much,
you should of course read *both* books and then choose which approach you
prefer.
The management summary is that Chris Date (cum suis) basically states that
you don't need to treat time as something different, because the relational
model is capable to treat time as a regular attribute -- you only need some
additional operators in your relational language. If you know Chris Date and
his opinion about the relational model, I guess you are not surprised ;-)
Kind regards,
Lex.
---------------------------------------------
visit my website at http://www.naturaljoin.nl
---------------------------------------------
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Poras, Henry R.
Sent: Monday, August 02, 2004 19:44
To: 'oracle-l@xxxxxxxxxxxxx'
Subject: RE: how to generate the output w/o using temp table
Lex,
How does this compare to the Richard Snodgrass book 'Developing
Time-Oriented
Database Applications in SQL'
(http://www.cs.arizona.edu/people/rts/tdbbook.pdf)?
Henry
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Lex de Haan
Sent: Monday, August 02, 2004 1:29 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: how to generate the output w/o using temp table
as an aside, if you are interested in some theory behind
this type of problems, the following book is a must:
Chris date, Hugh Darwen, and Nikos Lorentzos:
"Temporal Data and the Relational Model"
Morgan Kaufmann Publishers, ISBN 1-55860-855-9.
they introduce the concept of "packing" and "unpacking" data
over the time dimension -- which is the generalization of the issue here.
Kind regards,
Lex.
---------------------------------------------
visit my website at http://www.naturaljoin.nl
---------------------------------------------
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Daniel Fink
Sent: Monday, August 02, 2004 18:01
To: oracle-l@xxxxxxxxxxxxx
Subject: Re: how to generate the output w/o using temp table
Somehow, you need to iterate through a list of months between the start and
end dates and find all records that fall within that
range. If you have a calendar type table, you can use that. If not, you have
to get creative. I've included some code below (part
stolen from other posters, part from my own twisted mind). *IF* the number
of months requested is greater that the number of rows in
the vacation table, it will *not* work. A better solution would be to code
it in PL/SQL or another language.
Regards,
Daniel Fink
-- Binary/unsupported file stripped by Ecartis --
-- Type: text/x-vcard
-- File: Lex de Haan.vcf
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------
-- Binary/unsupported file stripped by Ecartis --
-- Type: text/x-vcard
-- File: Lex de Haan.vcf
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------
|

|