firefly-iii/app/Models/Category.php

<?php namespace FireflyIII\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

/**
 * Class Category
 *
 * @package FireflyIII\Models
 */
class Category extends Model
{
    use SoftDeletes;

    protected $fillable = ['user_id', 'name'];

    /**
     * @return array
     */
    public function getDates()
    {
        return ['created_at', 'updated_at', 'deleted_at'];
    }

    /**
     * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
     */
    public function transactionjournals()
    {
        return $this->belongsToMany('FireflyIII\Models\TransactionJournal', 'category_transaction_journal', 'category_id');
    }

    /**
     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
     */
    public function user()
    {
        return $this->belongsTo('FireflyIII\User');
    }

}