Elixir Language Ecto "and" clause in a Repo.get_by/3
Example
If you have an Ecto.Queryable, named Post, which has a title and an description.
You can fetch the Post with title: "hello" and description : "world" by performing :
MyRepo.get_by(Post, [title: "hello", description: "world"])
All of this is possible because Repo.get_by expects in second argument a Keyword List.
