How I can put composite keys in models in Laravel 5?

In Laravel 5, you can specify a composite key on a model by defining a protected $primaryKey property on the model and setting it to an array of the column names that make up the primary key. For example:

<?php

class ExampleModel extends Model
{
    protected $primaryKey = ['column_name_1', 'column_name_2'];
}

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You also have to make sure that the columns you use as the primary key in your migration have unique indexes.

<?php

$table->unique(['column_name_1', 'column_name_2']);

Additionally, you may also need to override some of the default Eloquent methods, such as getKeyName() or getKeyType() to make sure that Eloquent is able to work with composite keys correctly.