Let’s say you have a changeset for %Signup{} in signup_changeset. You could write something like this:
case Ecto.Changeset.apply_action(signup_changeset, :insert) do
{:ok, signup} ->
# use signup.email etc to populate Profile and
# Account records and save to the DB
{:error, changeset} ->
# do something to tell the caller about the errors in `changeset`
end
