Howto find neighbouring nodes of another type

Hello, all,

Some searching didn't result in an answer to my question, hence this question of mine here ...

I'd like to get to know how I could find charging stations with a restaurant in their immediate vicinity (roughly 100m, just naming a number). I have this idea I'd extract all of the area's charging stations in one file, and all restaurants in another file. But then : how can I find out the nodes which are in each other's close vicinity ? Or would it maybe be better to import OSM into a database of mine, and make a select query ?