Cargo is a terrific MediaWiki extension that lets you treat individual wiki pages as being rows in a table, and to have the columns of those tables defined centrally (by a template). Then you can query and format and export the data, pretty much turning MediaWiki into a database.
The main action that is hard with Cargo is updating many rows (i.e. pages) at once, because there's no easy way to insert single values to an infobox template invocation. I think I once got it working with the Data Transfer extension but there were a few problems.