如何使用Ecto连接多个存储库？

defp deps do
  [
    {:ecto, "~> 3.0"},
    # 其他依赖项...
  ]
end

config :my_app, MyApp.Repo,
  database: "primary_db",
  username: "username",
  password: "password",
  hostname: "localhost",
  port: 5432

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
end

users = MyApp.Repo.all(MyApp.User)

config :my_app, MyApp.SecondaryRepo,
  database: "secondary_db",
  username: "username",
  password: "password",
  hostname: "localhost",
  port: 5432

defmodule MyApp.SecondaryRepo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
end

users = MyApp.SecondaryRepo.all(MyApp.User)