From 742803b92704695486566a966679faa594ba35bc Mon Sep 17 00:00:00 2001
From: Danielwhyte <danwhy@gmail.com>
Date: Wed, 12 Sep 2018 16:12:03 +0100
Subject: [PATCH] adds schema for address book, #1

---
 README.md                                     | 95 ++++++++++++++++++-
 config/dev.exs                                | 12 ++-
 config/test.exs                               |  2 +-
 lib/append/address.ex                         | 23 +++++
 mix.exs                                       | 10 +-
 .../20180912142549_create_addresses.exs       | 23 +++++
 6 files changed, 154 insertions(+), 11 deletions(-)
 create mode 100644 lib/append/address.ex
 create mode 100644 priv/repo/migrations/20180912142549_create_addresses.exs

diff --git a/README.md b/README.md
index 3f1965c..522279d 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,14 @@ Make sure you have installed on your machine:
 + Phoenix: https://hexdocs.pm/phoenix/installation.html
 + PostgreSQL: https://www.postgresql.org/download/
 
-### Getting started
+Make sure you have a non-default PostgresQL user, with no more than `CREATEDB` privileges. If not, follow the steps below:
+
++ open psql by typing `psql` into your terminal
++ In psql, type:
+  + `CREATE USER append_only;`
+  + `ALTER USER append_only CREATEDB;`
+
+### 1. Getting started
 
 Make a new Phoenix app:
 
@@ -31,8 +38,92 @@ Type `y` when asked if you want to install the dependencies, then follow the ins
 cd append
 ```
 
-then `create the database` for your app:
+then, go into your generated config file. In `config/dev.exs` and `config/test.exs` you should see a section that looks like this:
+``` elixir
+# Configure your database
+config :append, Append.Repo,
+  adapter: Ecto.Adapters.Postgres,
+  username: "postgres",
+  password: "postgres",
+  ...
+```
+
+Change the username to your non-default PostgreSQL user:
+
+``` elixir
+  ...
+  username: "append_only",
+  ...
+```
+
+Once you've done this, `create the database` for your app:
 
 ```
 mix ecto.create
 ```
+
+### 2. Create the Schema
+
+We're going to use an address book as an example. run the following generator command to create our schema:
+
+```
+mix phx.gen.schema Address addresses name:string address_line_1:string address_line_2:string city:string postcode:string tel:string
+```
+
+This will create two new files:
++ `lib/append/address.ex`
++ `priv/repo/migrations/{timestamp}_create_addresses.exs`
+
+Before you follow the instructions in your terminal, we'll need to edit the generated migration file.
+
+The generated file should look like this:
+
+``` elixir
+defmodule Append.Repo.Migrations.CreateAddresses do
+  use Ecto.Migration
+
+  def change do
+    create table(:addresses) do
+      add(:name, :string)
+      add(:address_line_1, :string)
+      add(:address_line_2, :string)
+      add(:city, :string)
+      add(:postcode, :string)
+      add(:tel, :string)
+
+      timestamps()
+    end
+
+  end
+end
+```
+
+We need to edit it to remove update and delete privileges for our user:
+
+``` elixir
+defmodule Append.Repo.Migrations.CreateAddresses do
+  use Ecto.Migration
+
+  # Get name of our Ecto Repo module from our config
+  @repo :append |> Application.get_env(:ecto_repos) |> List.first()
+  # Get username of Ecto Repo from our config
+  @db_user Application.get_env(:append, @repo)[:username]
+
+  def change do
+    ...
+    execute("REVOKE UPDATE, DELETE ON TABLE addresses FROM #{@db_user}")
+  end
+end
+```
+
+Once this is done, run:
+```
+mix ecto.migrate
+```
+and you should see the following output:
+```
+[info] == Running Append.Repo.Migrations.CreateAddresses.change/0 forward
+[info] create table addresses
+[info] execute "REVOKE UPDATE, DELETE ON TABLE addresses FROM append_only"
+[info] == Migrated in 0.0s
+```
diff --git a/config/dev.exs b/config/dev.exs
index 75c8352..0a1372c 100644
--- a/config/dev.exs
+++ b/config/dev.exs
@@ -11,8 +11,14 @@ config :append, AppendWeb.Endpoint,
   debug_errors: true,
   code_reloader: true,
   check_origin: false,
-  watchers: [node: ["node_modules/brunch/bin/brunch", "watch", "--stdin",
-                    cd: Path.expand("../assets", __DIR__)]]
+  watchers: [
+    node: [
+      "node_modules/brunch/bin/brunch",
+      "watch",
+      "--stdin",
+      cd: Path.expand("../assets", __DIR__)
+    ]
+  ]
 
 # ## SSL Support
 #
@@ -51,7 +57,7 @@ config :phoenix, :stacktrace_depth, 20
 # Configure your database
 config :append, Append.Repo,
   adapter: Ecto.Adapters.Postgres,
-  username: "postgres",
+  username: "append_only",
   password: "postgres",
   database: "append_dev",
   hostname: "localhost",
diff --git a/config/test.exs b/config/test.exs
index 6dc55d4..9ad4192 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -12,7 +12,7 @@ config :logger, level: :warn
 # Configure your database
 config :append, Append.Repo,
   adapter: Ecto.Adapters.Postgres,
-  username: "postgres",
+  username: "append_only",
   password: "postgres",
   database: "append_test",
   hostname: "localhost",
diff --git a/lib/append/address.ex b/lib/append/address.ex
new file mode 100644
index 0000000..f6eae99
--- /dev/null
+++ b/lib/append/address.ex
@@ -0,0 +1,23 @@
+defmodule Append.Address do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+
+  schema "addresses" do
+    field :address_line_1, :string
+    field :address_line_2, :string
+    field :city, :string
+    field :name, :string
+    field :postcode, :string
+    field :tel, :string
+
+    timestamps()
+  end
+
+  @doc false
+  def changeset(address, attrs) do
+    address
+    |> cast(attrs, [:name, :address_line_1, :address_line_2, :city, :postcode, :tel])
+    |> validate_required([:name, :address_line_1, :address_line_2, :city, :postcode, :tel])
+  end
+end
diff --git a/mix.exs b/mix.exs
index 2721228..2d7653a 100644
--- a/mix.exs
+++ b/mix.exs
@@ -6,9 +6,9 @@ defmodule Append.Mixfile do
       app: :append,
       version: "0.0.1",
       elixir: "~> 1.4",
-      elixirc_paths: elixirc_paths(Mix.env),
-      compilers: [:phoenix, :gettext] ++ Mix.compilers,
-      start_permanent: Mix.env == :prod,
+      elixirc_paths: elixirc_paths(Mix.env()),
+      compilers: [:phoenix, :gettext] ++ Mix.compilers(),
+      start_permanent: Mix.env() == :prod,
       aliases: aliases(),
       deps: deps()
     ]
@@ -26,7 +26,7 @@ defmodule Append.Mixfile do
 
   # Specifies which paths to compile per environment.
   defp elixirc_paths(:test), do: ["lib", "test/support"]
-  defp elixirc_paths(_),     do: ["lib"]
+  defp elixirc_paths(_), do: ["lib"]
 
   # Specifies your project dependencies.
   #
@@ -54,7 +54,7 @@ defmodule Append.Mixfile do
     [
       "ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
       "ecto.reset": ["ecto.drop", "ecto.setup"],
-      "test": ["ecto.create --quiet", "ecto.migrate", "test"]
+      test: ["ecto.create --quiet", "ecto.migrate", "test"]
     ]
   end
 end
diff --git a/priv/repo/migrations/20180912142549_create_addresses.exs b/priv/repo/migrations/20180912142549_create_addresses.exs
new file mode 100644
index 0000000..e73a011
--- /dev/null
+++ b/priv/repo/migrations/20180912142549_create_addresses.exs
@@ -0,0 +1,23 @@
+defmodule Append.Repo.Migrations.CreateAddresses do
+  use Ecto.Migration
+
+  # Get name of our Ecto Repo module from our config
+  @repo :append |> Application.get_env(:ecto_repos) |> List.first()
+  # Get username of Ecto Repo from our config
+  @db_user Application.get_env(:append, @repo)[:username]
+
+  def change do
+    create table(:addresses) do
+      add(:name, :string)
+      add(:address_line_1, :string)
+      add(:address_line_2, :string)
+      add(:city, :string)
+      add(:postcode, :string)
+      add(:tel, :string)
+
+      timestamps()
+    end
+
+    execute("REVOKE UPDATE, DELETE ON TABLE addresses FROM #{@db_user}")
+  end
+end