# Using ULID in Laravel Framework

In a previous [post](https://muhamadhhassan.me/using-unique-identifiers-as-primary-key-in-mysql), we talked about how ULID can be a better choice for primary keys in MySQL than UUIDs. In this tutorial, we will go over how to use ULID in Laravel Framework.

ULID has been supported in Laravel since [v9.30.1](https://github.com/laravel/framework/releases/tag/v9.30.1) and has received some improvements in later releases So no third-party packages are needed to use it.

### Eloquent Models

Let's take an `Article` model as an example. First, we create the article's model and migration file as we normally do

```bash
php artisan make:model Article
```

In the `up` method inside the migration file, the table's primary key will be defined using the `ulid` method followed by the `primary` method.

```php
public function up(): void
{
    Schema::create('articles', function (Blueprint $table) {
        $table->ulid('id')->primary();
        $table->string('title');
        $table->text('body');
        $table->timestamps();
    });
}
```

What the [`ulid`](https://github.com/laravel/framework/blob/9.x/src/Illuminate/Database/Schema/Blueprint.php#L1288) method does is create a column of type `CHAR` and set its length to 26 bytes instead of the 36 bytes needed for UUIDs.

Then in the `Article` eloquent model, the `Illuminate\Database\Eloquent\Concerns\HasUlids` trait will be added

```php
<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Concerns\HasUlids;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Article extends Model
{
    use HasFactory, HasUlids;
}
```

Laravel also has a method in the `Illuminate\Database\Schema\Blueprint` class for creating foreign keys that references a table with ULID primary key.

In our example, we can add a `Comment` model and each comment belongs to one `Article`. The foreign key of the articles table is defined using the `foreignUlid` method

```php
public function up(): void
{
    Schema::create('comments', function (Blueprint $table) {
        $table->uuid('id')->primary();
        $table->string('body');
        $table->foreignUlid('article_id')->constrained();
        $table->timestamps();
    });
}
```

And the last method is `ulidMorphs` that create the columns needed for a polymorphic relation. Let's add another `Tag` model that can be linked to many models not just `Article`. The `taggables` table can be defined like this:

```php
public function up(): void
{
    Schema::create('taggables', function (Blueprint $table) {
        $table->foreignUlid('tag_id')->constrained();
        $table->ulidMorphs('taggable');
    });
}
```

### Str Facade

ULID can be created anywhere in your app using the `ulid` method in the `Illuminate\Support\Str` facade.

```php
Str::ulid()->toBase32()
```

The above statement returns the ULID and it will look something like this `01H0WXWP3XGAX0ZJVG7Q2E70FC`.

Finally, if you are interested in the implementation being used to generate ULID, check out the [Symfony UID](https://github.com/symfony/uid) component that Laravel uses.