Hello, I wish to code an app that will need to search and recover data in a database stored online in a NAS Server. Is there any tutorial/course/training/lesson/documentation/samples that could help me to learn how to do this? I've seen the API AssetDatabase.FindAssets. I suppose that this is the kind of things I should use.
No, AssetDatabase won't help you here. You will probably use UnityWebRequest and access your database through some sort of REST API.
AssetDatabase refers to Unity assets, as in assets within your project. As already mentioned a webserver front end for the database is usually the easiest route. It may also be possible to directly connect to the database from a Unity project, depending on what kind of database you're referring to.