What did we just do? Check out the diagram in the browser:
- We created three models -
Movie,Actor, andPart. - In the models, we used the
has_many :throughassociation to connect theMoviemodel to theActormodel through thePartmodel.
In this way, the has_many :through association sets up a many-to-many relationship between movies and actors.
Instructions
Now that there’s an association between Movie and Actor, let’s continue and add columns to the migration files:
Open the migration file in db/migrate/ for the movies table, and add the following columns:
- a
stringcolumn calledtitle - a
stringcolumn calledimage - a
stringcolumn calledrelease_year - a
stringcolumn calledplot
Next in the migration file for the actors table, and add the following columns:
- a
stringcolumn calledfirst_name - a
stringcolumn calledlast_name - a
stringcolumn calledimage - a
stringcolumn calledbio
Then in the migration file for the parts table, add the following lines. They add foreign keys that point to the movie and actor tables.
Run the migration to update the database with the three tables.
Open up db/seeds.rb. We’ve added a few items here to seed the database with movies and actors. Run bundle exec rake db:seed to seed the database with the data in db/seeds.rb.