Why do you use Ecto.Multi?

[Eiji]

This ebook would be really helpful for you (not only in Ecto.Multi):

The Little Ecto Cookbook (self-published) (free)

[click] The Ecto recipes were originally written for the “What’s new in Ecto 2” ebook and then made open-source by Plataformatec. Since then, the community has joined our efforts and made many contributions. The end result is this ebook, curated by Plataformatec, which includes a foreword and an exclusive chapter written by José Valim, creator of Elixir. The Plataformatec team brings an updated collection of recipes on how to best use different features of Ecto 3.1 and later. This free ebo…

It’s free and there is no sense to copy-paste it’s contents. I really recommend reading it.