Working with arrays stored on a database column

Hello,

Further to this topic, I have a column in a table sorting values as ‘1,2,5,7’ . For the sake of an example, they can be category IDs. I have a different table that lists ID_category and category_name.

What would be the best approach to have a query list the categorie_name concatenated by commas, instead of the stored IDs?
I’m also finding that I need a method to trend these values and wonder if I would have been better off to store them in a dedicated table - for things like graphs and grouping exercises.

I would very much welcome suggestions from more experienced users, it’s the first time I find myself in this use case.

Thanks!