I have a page that is querying a rather large database & then showing the results on the next page. I'm trying to show a loading spinner on the first page while the query is happening before it redirects to the results page.
Everything I've found is just showing loading spinners for ajax calls?
In you case, you need to use a Page Loader. A page loader is any kind of animation that visually communicates to a visitor that the page is loading and to just sit tight for a few seconds. Without a page loader, a visitor might think your site is being unresponsive and just click away in frustration. A page loader also provides a small distraction which can actually makes the wait seem much shorter.
You can use this: https://css-tricks.com/css-page-loader-example/
If you want something more cool and modern, try one of these: http://github.hubspot.com/pace/docs/welcome/