<p>So I decided to use UUIDs as primary keys for the resources I am creating in my webapp. The reason is cause I don't like the default one "auto increment integer".</p>

<p>So how to achieve this in Phoenix?</p>

<h2>
  <a name="1-add-a-custom-schema" href="#1-add-a-custom-schema" class="anchor">
  </a>
  1. Add a custom schema
</h2>

<p>The idea with the code below is to override <code>Ecto.Schema</code> with our new config<br>
</p>

<div class="highlight js-code-highlight">
<pre class="highlight plaintext"><code># lib/your_app/schema.ex

defmodule YourApp.Schema do
  defmacro __using__(_) do
    quote do
      use Ecto.Schema
      @primary_key {:id, :binary_id, autogenerate: true}
      @foreign_key_type :binary_id
    end
  end
end
</code></pre>
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<p>Now, on your schemas you should use <code>use YourApp.Schema</code> instead of <code>Ecto.Schema</code></p>

<h2>
  <a name="2-fix-your-migration" href="#2-fix-your-migration" class="anchor">
  </a>
  2. Fix your Migration!
</h2>

<p>This one is a very important step. The reason why is because by default when your run your migration it will try to create your tables using the default id (auto increment integer) to fix this is very simple<br>
</p>

<div class="highlight js-code-highlight">
<pre class="highlight plaintext"><code># config/config.exs

config :your_app, YourApp.Repo, migration_primary_key: [name: :id, type: :binary_id]
</code></pre>
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<p>Now when you run your migrations to create your tables the id will be of type binary_id :D.</p>

<p>And that's it. Profit :).</p>



So I decided to use UUIDs as primary keys for the resources I am creating in my webapp. The reason is cause I don't like the default one "auto increment integer".

So how to achieve this in Phoenix?

## 1. Add a custom schema
The idea with the code below is to override `Ecto.Schema` with our new config

```
# lib/your_app/schema.ex

defmodule YourApp.Schema do
  defmacro __using__(_) do
    quote do
      use Ecto.Schema
      @primary_key {:id, :binary_id, autogenerate: true}
      @foreign_key_type :binary_id
    end
  end
end
```

Now, on your schemas you should use `use YourApp.Schema` instead of `Ecto.Schema`

## 2. Fix your Migration!

This one is a very important step. The reason why is because by default when your run your migration it will try to create your tables using the default id (auto increment integer) to fix this is very simple

```
# config/config.exs

config :your_app, YourApp.Repo, migration_primary_key: [name: :id, type: :binary_id]
```
Now when you run your migrations to create your tables the id will be of type binary_id :D.

And that's it. Profit :).

So I decided to use UUIDs as primary keys for the resources I am creating in my webapp. The reason is...

How to: use UUID as Primary Keys in Phoenix