Need help with 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 | skye | 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?
Originally published on Semantic Nodix
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