firefly-iii/app/Models/CurrencyExchangeRate.php

<?php
/**
 * CurrencyExchange.php
 * Copyright (c) 2017 thegrumpydictator@gmail.com
 * This software may be modified and distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International License.
 *
 * See the LICENSE file for details.
 */

declare(strict_types=1);

namespace FireflyIII\Models;


use FireflyIII\User;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

/**
 * Class CurrencyExchange
 *
 * @package FireflyIII\Models
 */
class CurrencyExchangeRate extends Model
{

    protected $dates = ['created_at', 'updated_at', 'date'];

    /**
     * @return BelongsTo
     */
    public function fromCurrency(): BelongsTo
    {
        return $this->belongsTo(TransactionCurrency::class, 'from_currency_id');
    }

    /**
     * @return BelongsTo
     */
    public function toCurrency(): BelongsTo
    {
        return $this->belongsTo(TransactionCurrency::class, 'to_currency_id');
    }

    /**
     * @return BelongsTo
     */
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

}