Roles

idRole
1Actor
2Director

People

idNameBirth_year
1John Doe1975
2Jane Smith1980

Movies

idTitleRelease_date
1Movie12000-01-01
2Movie22005-06-01

MovieRoles

MovieIdPersonIdRoleId
(→ Movies.id)(→ People.id)(→ Roles.id)
111
221
312
422

DirectorMovies

DirectorIdMovieId
(→ People.id)(→ Movies.id)
11
22

ActorMovies

ActorIdMovieId
(→ People.id)(→ Movies.id)
11
22
33
44