We use TWiki very heavily. We use it for documentation, and not (much) structured data, but I have noted that it has far better support for structured data than any other wikis I've used. It has a large number of data imports (including from Excel and other spreadsheets), and some good form management tools. So, you can build a form for entering structured data, and that structured data goes into the wiki (and can be edited on the same form or directly in wikitext).
It's quite intimidating from a customization perspective, but since it has so many features built in, you probably won't need to do a lot of coding to make it do what you want. Theming it can be a challenge, though. I also don't love the syntax. But you can't beat it for features. It does everything any other wiki does, plus a bunch of other app building types of functionality that don't exist anywhere else (or at least, nowhere else I've seen).
It's quite intimidating from a customization perspective, but since it has so many features built in, you probably won't need to do a lot of coding to make it do what you want. Theming it can be a challenge, though. I also don't love the syntax. But you can't beat it for features. It does everything any other wiki does, plus a bunch of other app building types of functionality that don't exist anywhere else (or at least, nowhere else I've seen).