I am attempting to make an ER diagram where the customer buys music online. We were just in the first weeks of tackling database so a lot of topics isn't introduced yet. Here's what I've done so far:
I know there are things that are lacking or things that can still be improved, I just want to know:
How can I categorize the artist into solo, group or band? And how can I give them relationships to the 'artist' entity? Also can is it necessary or I can just disregard that option?
Is my 'list of genre', 'list of album', and 'list of track' okay to use?
On the 'purchase' entity, what happens when the customer would only buy tracks and not albums? Are my attributes fine?