I’m dealing with this situation. I’ve got three tables in SQL SERVER called Movies, Series and Orders.
Orders has an ItemId where this could be a MovieId (Movies PK) or SerieId (Series PK). I mean, in Orders table could have records where are from movies of series.
I don’t know how to maintain this relationship or which could be the best way to implement it. Until I know, I only can create 1 to 1 or 1 to many relationships between 2 tables, not for 3.
Thanks in advance.
In this case I think it would be better to store Movies and Series in the same table with the common attributes incl. a column which indicates the type (Movie or Serie) and then have the additional attributes in seperate tables (if you want to normalize) or even in the same table (in order to avoid joins).