Ecto - Updating nested (Polymorphic) Associations - nested

Question

How does one update a model with a nested association (using [Elixir, Phoenix, Ecto])?
I've tried the following, to treat it as part of it's parent update, without success (using the platformatec blog as inspiration).
Models:
schema "user" do
has_one :address, {"users_addresses", MyApp.Address}, foreign_key: :assoc_id
end
#required_fields ~w(address)
------
# Materialized in users_addresses table
schema "abstract table: addresses" do
field :assoc_id, :integer
field :street_address, :string
end
Request (PATCH):
{
"user" => {
"address" => {
"street_address" => "1234"
}
}
}
Controller:
def update(conn, %{"id" => id, "user" => params}) do
user = MyApp.Repo.get(User, id)
|> MyApp.Repo.preload [:address]
if is_nil(user) do
send_resp(conn, 404, "")
else
changeset = User.changeset(user, params)
if changeset.valid? do
case MyApp.Repo.update(changeset) do
{:ok, model} -> send_resp(conn, 204, "")
{:error, changeset} -> conn
|> put_status(:unprocessable_entity)
|> render(MyApp.ChangesetView, "error.json", changeset: changeset)
end
else
conn
|> put_status(:unprocessable_entity)
|> render(MyApp.ChangesetView, "error.json", changeset: changeset)
end
end
end
Changeset (from logs):
%Ecto.Changeset{action: nil,
changes: %{address: %Ecto.Changeset{action: :insert, changes: %{street_address: "1234"},
constraints: [],
....
model: %MyApp.User{__meta__: #Ecto.Schema.Metadata<:loaded>,
address: %MyApp.Address{__meta__: #Ecto.Schema.Metadata<:loaded>,
assoc_id: 1229, id: 308,
street_address: "41423 Jakubowski Village"
....
}
}
}
Error: Fixed as of Ecto v1.0.3 or later
** (exit) an exception was raised:
** (Postgrex.Error) ERROR (undefined_table): relation "abstract table: addresses" does not exist
(ecto) lib/ecto/adapters/sql.ex:479: Ecto.Adapters.SQL.model/6
(ecto) lib/ecto/repo/model.ex:219: Ecto.Repo.Model.apply/4
(ecto) lib/ecto/repo/model.ex:71: anonymous fn/10 in Ecto.Repo.Model.insert/4
(ecto) lib/ecto/repo/model.ex:340: anonymous fn/3 in Ecto.Repo.Model.wrap_in_transaction/8
(ecto) lib/ecto/adapters/sql.ex:531: anonymous fn/10 in Ecto.Adapters.SQL.transaction/3
(ecto) lib/ecto/pool.ex:262: Ecto.Pool.inner_transaction/3
(ecto) lib/ecto/adapters/sql.ex:534: Ecto.Adapters.SQL.transaction/3
(ecto) lib/ecto/association.ex:368: Ecto.Association.Has.on_repo_action/7

Answer 1

(Postgrex.Error) ERROR (undefined_table): relation "abstract table: addresses" does not exist was due to a bug, which should be fixed in Ecto v1.0.3 or later.
The code above is missing an id for the address, without this, Ecto will insert a new resource instead of updating an existing one.
Request (PATCH):
{
"user" => {
"address" => {
"id" => 4,
"street_address" => "1234"
}
}
}
The new controller code, including some of JoseValims suggested improvements:
def update(conn, %{"id" => id, "user" => params}) do
user = MyApp.Repo.get!(User, id)
|> MyApp.Repo.preload [:address
changeset = User.changeset(user, params)
case MyApp.Repo.update(changeset) do
{:ok, model} -> send_resp(conn, 204, "")
{:error, changeset} -> conn
|> put_status(:unprocessable_entity)
|> render(MyApp.ChangesetView, "error.json", changeset: changeset)
end
end
Or, in this situation since the address is both required and has_one, the id can be added server side:
def update(conn, %{"id" => id, "user" => params}) do
user = MyApp.Repo.get!(User, id)
|> MyApp.Repo.preload [:address]
address = params["address"]
address = Map.put address, "id", user.address.id
params = Map.put params, "address", address
changeset = User.changeset(user, params)
case MyApp.Repo.update(changeset) do
{:ok, model} -> send_resp(conn, 204, "")
{:error, changeset} -> conn
|> put_status(:unprocessable_entity)
|> render(MyApp.ChangesetView, "error.json", changeset: changeset)
end
end