Thread: Re: XML ouput for psql
XSLT could be used to convert virtually any xml table format directly into an insert statement. For me, this is better than using a programming language plus a parser. XSLT is quite powerful and fast and is build on top of xpath, and is a closer fit to the declarative programming model of sql. Validation could be done at the xslt stage or with schemas, which I prefer. > Acually, the difficult part has been getting the information back > into the database. Getting it out is a very simple query. I imagine > that every language/environment has an SQL->XML library somewhere, > but I wasn't able to find something that would go from XML to SQL. >
I would like to see PostgreSQL eventually support XQuery: http://www.w3.org/TR/xquery/ http://www.w3.org/TR/query-datamodel/ I see potentially an alternative front end called xsql, providing substantially the same functionality as psql, only using XQuery syntax and optionally returning recordsets as XML. Anybody want to put together a team to explore this seriously? There are probably several non-trivial semantic issues on the back end, but I only dimly grasp them at this point. - Bob Calco %% -----Original Message----- %% From: pgsql-hackers-owner@postgresql.org %% [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Merlin Moncure %% Sent: Wednesday, March 05, 2003 8:16 AM %% To: Alan Gutierrez %% Cc: pgsql-hackers@postgresql.org %% Subject: Re: [HACKERS] XML ouput for psql %% %% %% XSLT could be used to convert virtually any xml table format directly %% into an insert statement. For me, this is better than using a %% programming language plus a parser. XSLT is quite powerful and fast and %% is build on top of xpath, and is a closer fit to the declarative %% programming model of sql. Validation could be done at the xslt stage or %% with schemas, which I prefer. %% %% %% > Acually, the difficult part has been getting the information back %% > into the database. Getting it out is a very simple query. I imagine %% > that every language/environment has an SQL->XML library somewhere, %% > but I wasn't able to find something that would go from XML to SQL. %% > %% %% ---------------------------(end of broadcast)--------------------------- %% TIP 3: if posting/reading through Usenet, please send an appropriate %% subscribe-nomail command to majordomo@postgresql.org so that your %% message can get through to the mailing list cleanly
Bob Calco writes: > I would like to see PostgreSQL eventually support XQuery: The specification is here: ftp://sqlstandards.org/SC32/WG3/Progression_Documents/FCD/4FCD1-14-XML-2002-03.txt Go for it. -- Peter Eisentraut peter_e@gmx.net
Thanks for the link - I think I just may give it a go. :) - Bob %% -----Original Message----- %% From: pgsql-hackers-owner@postgresql.org %% [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Peter Eisentraut %% Sent: Wednesday, March 05, 2003 5:39 PM %% To: Bob Calco %% Cc: Merlin Moncure; Alan Gutierrez; pgsql-hackers@postgresql.org %% Subject: Re: [HACKERS] XML ouput for psql %% %% %% Bob Calco writes: %% %% > I would like to see PostgreSQL eventually support XQuery: %% %% The specification is here: %% %% ftp://sqlstandards.org/SC32/WG3/Progression_Documents/FCD/4FCD1-1 %% 4-XML-2002-03.txt %% %% Go for it. %% %% -- %% Peter Eisentraut peter_e@gmx.net %% %% %% ---------------------------(end of broadcast)--------------------------- %% TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org %%
* Merlin Moncure <merlin.moncure@rcsonline.com> [2003-03-05 10:02]: > > Acually, the difficult part has been getting the information back > > into the database. Getting it out is a very simple query. I imagine > > that every language/environment has an SQL->XML library somewhere, > > but I wasn't able to find something that would go from XML to SQL. > XSLT could be used to convert virtually any xml table format directly > into an insert statement. For me, this is better than using a > programming language plus a parser. XSLT is quite powerful and fast and > is build on top of xpath, and is a closer fit to the declarative > programming model of sql. Validation could be done at the xslt stage or > with schemas, which I prefer. XSLT, or Perl, or anything. That's not a problem. It becomes a problem when I have to hand write insert/update statements for every type of element in an XML document. <person> <first-name>Alan</first-name> <last-name>Gutierrez</last-name> <ssn>1234565789</ssn> </person> If I feed this document to a database I want it to absorb the document, inserting if doesn't already exists, updating it if it does. There is no way to test for the existstence of a record in a person table during an XSLT transformation. -- Alan Gutierrez - ajglist@izzy.net http://khtml-win32.sourceforge.net/ - KHTML on Windows