elixir - Unique index constraint not working in Phoenix app -

in phoenix app have user model follows:

defmodule myapp.user   use myapp.web, :model    schema "users"     field :username, :string, unique: true     field :email, :string, unique: true     field :crypted_password, :string     field :password, :string, virtual: true      timestamps   end    @required_fields ~w(email password username)   @optional_fields ~w()    @doc """   creates changeset based on `model` , `params`.    if no params provided, invalid changeset returned   no validation performed.   """   def changeset(model, params \\ :empty)     model     |> cast(params, @required_fields, @optional_fields)     |> unique_constraint(:email)     |> unique_constraint(:username)     |> validate_format(:email, ~r/@/)     |> validate_length(:password, min: 5)   end end 

i have following migration:

defmodule myapp.repo.migrations.createuser   use ecto.migration    def change     create table(:users)       add :email, :string       add :username, :string       add :crypted_password, :string        timestamps     end      create unique_index(:users, [:email])     create unique_index(:users, [:username])   end end 

and have registration_controller_ex follows:

defmodule myapp.registrationcontroller   use myapp.web, :controller   alias myapp.user    def new(conn, _params)     changeset = user.changeset(%user{})     render conn, changeset: changeset   end    def create(conn, %{"user" => user_params})     changeset = user.changeset(%user{}, user_params)      if changeset.valid?       user = myapp.registration.create(changeset, myapp.repo)       conn       |> put_flash(:info, "your account created")       |> redirect(to: "/")     else       conn       |> put_flash(:info, "unable create account")       |> render("new.html", changeset: changeset)     end   end end 

so, i'm pretty sure username , email fields in user unique indexes. make sure unique calling unique_constraint validate user.changeset. however, when in interface create user same email , username preivously created one, changeset validated , user "created". (it's not created, when database nothing added)

i following on server logs, changeset.valid? true.

[debug] begin [] ok query=139.3ms queue=8.2ms [debug] insert "users" ("crypted_password", "email", "inserted_at", "updated_at", "username") values ($1, $2, $3, $4, $5) returning "id" ["$2b$12$mn1yxfuglmijyxsezn0sjuuvs9u1jrdytrr9d8xqsaqdh.d2srrxa", "email@gmail.com", {{2015, 9, 30}, {11, 7, 25, 0}}, {{2015, 9, 30}, {11, 7, 25, 0}}, "username"] error query=5.5ms [debug] rollback [] ok query=0.4ms 

also, other things in user.changeset function (such minimum password length , other things) reported user , working fine. it's unique indexes :email , :username failing reported.

the unique_constraint checked database , triggered upon inserting record. calling changeset.valid? not check constraints , in case return true. need check return tuple of repo insert , act on like:

def create(conn, %{"user" => user_params})   changeset = user.changeset(%user{}, user_params)   case  myapp.repo.insert changeset     {:ok, changeset} ->        conn       |> put_flash(:info, "your account created")       |> redirect(to: "/")           {:error, changeset} ->       conn       |> put_flash(:info, "unable create account")       |> render("new.html", changeset: changeset)         end end 

now changeset.errors enriched , should able fetch error changeset.errors[:email]