- From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
- Date: Tue, 11 Nov 2003 17:07:12 +0000
- To: www-rdf-interest@w3.org
On Tue, Nov 11, 2003 at 05:04:35 +0100, Leo Sauermann wrote: > because from your answer I think you understood that i wanted to have > some SQL standard stuff written in the Rdf-Query standard. Like "to > implement a RDF-Query, you have to use these internal SQL queries" > thats not what I meant, the OUTER JOIN problem is a RDF problem you have > when you try to use RDQL (a very popular query language, imho). ... > but with today's RDQL this is more complicated: > if there is no <foaf:image> triple for leo, you don't get any data at > all. Yes, agreed, this is a problem. I think that SQL behaviour is a LEFT JOIN though. I'm not sure how an OUTER JOIN would map to RDQL, but it would probably give you more rows than that. http://www.w3schools.com/sql/sql_join.asp - Steve
Received on Tuesday, 11 November 2003 12:09:28 UTC