Table Names

After glancing at the example above, you may have noticed that we did not tell Eloquent which database table corresponds to our Flight model. By convention, the "snake case", plural name of the class will be used as the table name unless another name is explicitly specified. So, in this case, Eloquent will assume the Flight model stores records in the flights table, while an AirTrafficController model would store records in an air_traffic_controllers table.

If your model's corresponding database table does not fit this convention, you may manually specify the model's table name by defining a table property on the model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Flight extends Model
{
/**
* The table associated with the model.
*
* @var string
*/
protected $table = 'my_flights';
}

Primary Keys

Eloquent will also assume that each model's corresponding database table has a primary key column named id. If necessary, you may define a protected $primaryKey property on your model to specify a different column that serves as your model's primary key:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Flight extends Model
{
/**
* The primary key associated with the table.
*
* @var string
*/
protected $primaryKey = 'flight_id';
}

In addition, Eloquent assumes that the primary key is an incrementing integer value, which means that Eloquent will automatically cast the primary key to an integer. If you wish to use a non-incrementing or a non-numeric primary key you must define a public $incrementing property on your model that is set to false:

<?php

class Flight extends Model
{
/**
* Indicates if the model's ID is auto-incrementing.
*
* @var bool
*/
public $incrementing = false;
}

If your model's primary key is not an integer, you should define a protected $keyType property on your model. This property should have a value of string:

<?php

class Flight extends Model
{
/**
* The data type of the auto-incrementing ID.
*
* @var string
*/
protected $keyType = 'string';
}

"Composite" Primary Keys

Eloquent requires each model to have at least one uniquely identifying "ID" that can serve as its primary key. "Composite" primary keys are not supported by Eloquent models. However, you are free to add additional multi-column, unique indexes to your database tables in addition to the table's uniquely identifying primary key.

UUID & ULID Keys

Instead of using auto-incrementing integers as your Eloquent model's primary keys, you may choose to use UUIDs instead. UUIDs are universally unique alpha-numeric identifiers that are 36 characters long.

If you would like a model to use a UUID key instead of an auto-incrementing integer key, you may use the Illuminate\Database\Eloquent\Concerns\HasUuids trait on the model. Of course, you should ensure that the model has a UUID equivalent primary key column:

use Illuminate\Database\Eloquent\Concerns\HasUuids;
use Illuminate\Database\Eloquent\Model;

class Article extends Model
{
use HasUuids;

// ...
}

$article = Article::create(['title' => 'Traveling to Europe']);

$article->id; // "8f8e8478-9035-4d23-b9a7-62f4d2612ce5"

By default, The HasUuids trait will generate "ordered" UUIDs for your models. These UUIDs are more efficient for indexed database storage because they can be sorted lexicographically.

You can override the UUID generation process for a given model by defining a newUniqueId method on the model. In addition, you may specify which columns should receive UUIDs by defining a uniqueIds method on the model:

use Ramsey\Uuid\Uuid;

/**
* Generate a new UUID for the model.
*
* @return string
*/
public function newUniqueId()
{
return (string) Uuid::uuid4();
}

/**
* Get the columns that should receive a unique identifier.
*
* @return array
*/
public function uniqueIds()
{
return ['id', 'discount_code'];
}