rswcj Posted March 12, 2019 Share Posted March 12, 2019 A quick question. Why do you need a movies-actors table on page 174 (Chapter 6)? Why can't actors have one to many relationship with movies just as directors have, requiring only 3 tables in the cinema database. Thx! Link to comment Share on other sites More sharing options...
Larry Posted March 17, 2019 Share Posted March 17, 2019 Good question! Actors have a many-to-many relationship with movies because each actor can be in multiple movies and each movie has multiple actors. A rule in this model is that each movie only has a single director, so there's a one-to-many relationship between directors and movies (although in real life some movies have more than one director these days). Link to comment Share on other sites More sharing options...
Recommended Posts