From 6037c588163b6c88beb57ef7765afb2c8bbe20d8 Mon Sep 17 00:00:00 2001
From: datafoo <34766150+datafoo@users.noreply.github.com>
Date: Tue, 5 Feb 2019 15:51:13 +0100
Subject: [PATCH] Use `timestamp with time zone` for timestamp fields in
 `projection_versions`.

Fixes #20.
---
 CHANGELOG.md                                  | 10 +-
 README.md                                     | 98 +++++++++----------
 lib/projections/ecto.ex                       |  2 +-
 ...70609113553_create_projection_versions.exs |  2 +-
 ..._create_projection_version_with_prefix.exs |  2 +-
 5 files changed, 61 insertions(+), 53 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c4c1421..85f3f54 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,15 @@
 - Add `.formatter.exs` to Hex package ([#19](https://github.com/commanded/commanded-ecto-projections/pull/19)).
 - Add microseconds to timestamp fields in `projection_versions` ([#22](https://github.com/commanded/commanded-ecto-projections/pull/22)).
 
+### Upgrading
+
+- Upgrade your existing `projection_versions` table by running:
+
+  ```sql
+  ALTER TABLE projection_versions ALTER COLUMN inserted_at TYPE timestamp with time zone USING inserted_at AT TIME ZONE 'UTC';
+  ALTER TABLE projection_versions ALTER COLUMN updated_at TYPE timestamp with time zone USING updated_at AT TIME ZONE 'UTC';
+  ```
+
 ## v0.8.0
 
 ### Enhancements
@@ -55,7 +64,6 @@
 
 - Allow an Ecto schema prefix to be defined in config or per handler ([#4](https://github.com/commanded/commanded-ecto-projections/pull/4)).
 
-
 ## v0.4.0
 
 ### Enhancements
diff --git a/README.md b/README.md
index 8a12e89..80d6cb8 100644
--- a/README.md
+++ b/README.md
@@ -30,61 +30,61 @@ You should already have [Ecto](https://github.com/elixir-ecto/ecto) installed an
 
 1. Add `commanded_ecto_projections` to your list of dependencies in `mix.exs`:
 
-    ```elixir
-    def deps do
-      [
-        {:commanded_ecto_projections, "~> 0.8"},
-      ]
-    end
-    ```
+   ```elixir
+   def deps do
+     [
+       {:commanded_ecto_projections, "~> 0.8"},
+     ]
+   end
+   ```
 
 2. Configure `commanded_ecto_projections` with the Ecto repo used by your application:
 
-    ```elixir
-    config :commanded_ecto_projections,
-      repo: MyApp.Projections.Repo
-    ```
+   ```elixir
+   config :commanded_ecto_projections,
+     repo: MyApp.Projections.Repo
+   ```
 
-    Or alternatively in case of umbrella application define it later per projection:
+   Or alternatively in case of umbrella application define it later per projection:
 
-    ```elixir
-    defmodule MyApp.ExampleProjector do
-      use Commanded.Projections.Ecto,
-        name: "example_projection",
-        repo: MyApp.Projections.Repo
+   ```elixir
+   defmodule MyApp.ExampleProjector do
+     use Commanded.Projections.Ecto,
+       name: "example_projection",
+       repo: MyApp.Projections.Repo
 
-      ...
-    end
-    ```
+     ...
+   end
+   ```
 
 3. Generate an Ecto migration in your app:
 
-    ```console
-    $ mix ecto.gen.migration create_projection_versions
-    ```
+   ```console
+   $ mix ecto.gen.migration create_projection_versions
+   ```
 
 4. Modify the generated migration, in `priv/repo/migrations`, to create the `projection_versions` table:
 
-    ```elixir
-    defmodule CreateProjectionVersions do
-      use Ecto.Migration
+   ```elixir
+   defmodule CreateProjectionVersions do
+     use Ecto.Migration
 
-      def change do
-        create table(:projection_versions, primary_key: false) do
-          add :projection_name, :text, primary_key: true
-          add :last_seen_event_number, :bigint
+     def change do
+       create table(:projection_versions, primary_key: false) do
+         add :projection_name, :text, primary_key: true
+         add :last_seen_event_number, :bigint
 
-          timestamps()
-        end
-      end
-    end
-    ```
+         timestamps(type: :timestamptz)
+       end
+     end
+   end
+   ```
 
-4. Run the Ecto migration:
+5. Run the Ecto migration:
 
-    ```console
-    $ mix ecto.migrate
-    ```
+   ```console
+   $ mix ecto.migrate
+   ```
 
 ### Schema Prefix
 
@@ -250,19 +250,19 @@ To rebuild a projection you will need to:
 
 1. Delete the row containing the last seen event for the projection name:
 
-    ```SQL
-    delete from projection_versions
-    where projection_name = 'example_projection';
-    ```
+   ```SQL
+   delete from projection_versions
+   where projection_name = 'example_projection';
+   ```
 
 2. Truncate the tables that are being populated by the projection, and restart their identity:
 
-    ```SQL
-    truncate table
-      example_projections,
-      other_projections
-    restart identity;
-    ```
+   ```SQL
+   truncate table
+     example_projections,
+     other_projections
+   restart identity;
+   ```
 
 You will also need to reset the event store subscription for the commanded event handler. This is specific to whichever event store you are using.
 
diff --git a/lib/projections/ecto.ex b/lib/projections/ecto.ex
index 03a3806..f1ce999 100644
--- a/lib/projections/ecto.ex
+++ b/lib/projections/ecto.ex
@@ -130,7 +130,7 @@ defmodule Commanded.Projections.Ecto do
         schema "projection_versions" do
           field(:last_seen_event_number, :integer)
 
-          timestamps(type: :naive_datetime_usec)
+          timestamps(type: :utc_datetime_usec)
         end
 
         @required_fields ~w(last_seen_event_number)a
diff --git a/priv/repo/migrations/20170609113553_create_projection_versions.exs b/priv/repo/migrations/20170609113553_create_projection_versions.exs
index ab6c652..ecdcbeb 100644
--- a/priv/repo/migrations/20170609113553_create_projection_versions.exs
+++ b/priv/repo/migrations/20170609113553_create_projection_versions.exs
@@ -6,7 +6,7 @@ defmodule Commanded.Projections.Repo.Migrations.CreateProjectionVersions do
       add :projection_name, :text, primary_key: true
       add :last_seen_event_number, :bigint
 
-      timestamps()
+      timestamps(type: :timestamptz)
     end
   end
 end
diff --git a/priv/repo/migrations/20170929080308_create_projection_version_with_prefix.exs b/priv/repo/migrations/20170929080308_create_projection_version_with_prefix.exs
index d4b965b..dc0efa8 100644
--- a/priv/repo/migrations/20170929080308_create_projection_version_with_prefix.exs
+++ b/priv/repo/migrations/20170929080308_create_projection_version_with_prefix.exs
@@ -8,7 +8,7 @@ defmodule Commanded.Projections.Repo.Migrations.CreateProjectionVersionWithPrefi
       add :projection_name, :text, primary_key: true
       add :last_seen_event_number, :bigint
 
-      timestamps()
+      timestamps(type: :timestamptz)
     end
   end