defmodule TestCommandMultiConcat do @moduledoc false defstruct [ :id, :name, :email, :description ] end defimpl Commanded.Middleware.Uniqueness.UniqueFields, for: TestCommandMultiConcat do def unique(%TestCommandMultiConcat{id: id}), do: [ {[:name, :email], "not unique", id, ignore_case: [:email]}, {:description, "not unique", id} ] end