WWW2006 Social Wiki

The WWW2006 conference next week has a social wiki. So people can talk about evening activities, about planning BOF-Sessions, about their drinking habits. If you're coming to the conference, go there, make a page for yourself. I think it would be fun to capture the information, and to see how much data we can get together... data? Oh, yes, forgot to tell you: the WWW2006 wiki is running on Semantic Mediawiki.

Yay!

Let's show how cool this thing can get!

Semantic Mediawiki 0.4 - Knowledge Inside!

Until now, Semantic MediaWiki was kind of a nerds project. Yes, you could get a lot of information out in RDF, and actually, I used it as an RDF editor more than once -- but heck, what normal person needs that?

Now, with the freshly implemented feature, the advantages of a Semantic MediaWiki over a normal MediaWiki should become obvious: you can simply ask the wiki for stuff! Wiki, what are the 10 biggest city in the US? Put a list here. Or, wiki, what is the height of the current German chancellor? Put the info here. I have made a writeup on those inline queries on our demo wiki. Go there, read it.

But a lot of other things made it into the 0.4 release. Here's Markus' list:

• Improved output for Special:Relations and Special:Attributes: usage of
• relations and attributes is now counted
• Improved ontology import feature, allowing to import ontologies and to update existing pages with new ontological information
• Experimental suport for date/time datatype
• More datypes with units: mass and time duration
• Support for EXP-notation with numbers, as e.g. 2.345e13. Improved number formating in infobox.
• Configurable infobox: infobox can be hidden if empty, or switched off completely. This also works around a bug with MediaWiki galeries.
• Prototype version of Special:Types, showing all available datatypes with their names in the current language setting.
• "[[:located in::Paris]]" will now be rendered as "located in [[Paris]]"
• More efficient storage: changed database layout, indexes for fast search
• Code cleaned up, new style guidelines
• Bugfixes, a lot of Bugixes

Thanks to everyone who contributed and still contributes to the project! And, connected to this, thanks to the answers to my last blog entry -- I will write more on this tomorrow.

Need help wtih SQL

But I have no time to write it down... I will sketch my problem, and hopefully get an answer (I've started this blog in the morning, and now I need to close it, cause I have to leave).

Imagine I have following table (a triple store):

Subject	Predicate	Object
Adam	yahoo im	adam@net
Adam	skype	adam
Berta	skype	berta

How do I make a query that returns me the following table:

Subject	o1	o2
Adam	adam@net	adam
Berta	-	berta

The problems are the default value in the middle lower cell. The rest works (as maybe seen in the Semantic Mediawiki code, file includes/SMW_InlineQueries.php -- note that the CVS is not up to date for now, because SourceForge's CVS is down for days!)

It should work in general, with as many columns as I like on the answer table (based on the predicates in the first one).

Oh, and if you solved this -- or have an idea -- it would be nice if it worked with MySQL 4.0, i.e. without Subqueries.

Any ideas?