One-to-many associations

- [Host] In the last movie,…we saw how to use one-to-one associations.…Now let's build on that…to understand how to work with one-to-many associations.…One-to-many associations are gonna be similar…to one-to-one associations,…but there are a few main differences that I wanna highlight.…First, one-to-many associations…are gonna be much more commonly used.…In a typical application, you'll rarely use one-to-one,…but you'll use one-to-many the most often.…Second, because we have one object related to many objects,…we're gonna use plural names.…That's both gonna be true when we define the association…and also when we call the methods on it.…

We'll see those in a moment.…And third, the relationship…is going to return an array of objects back to us…instead of a single object.…And that just makes sense, right?…If we're going to have many records associated with it,…we're going to have to store those in an array…so that it can hold all of those records.…You use a one-to-many association…when one object has many objects which belong to it,…