Update Records with Associations
Learn how to update records with associations.
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We just looked at how to work with cast_assoc when we create a new parent record. Let’s now look at what happens when we’re updating an existing record. Before we do, if you’ve been following along on a local setup, let’s reset the database one more time to clean the slate by using mix ecto.reset
Make changes using cast_assoc
Now let’s make some changes to the Artist and Album records for Bill Evans. You should have an Artist record and two Album records if you’ve just reset your database. We can confirm that with the following bit of code.
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artist = Repo.get_by(Artist, name: "Bill Evans")\|> Repo.preload(:albums)IO.inspect Enum.map(artist.albums, &({&1.id, &1.title}))
It’s OK if the ids in your output don’t match the ones shown here, but the titles should be the same. ...