用于验证规则的空表上的计数

Question

我制定了一个自定义验证规则fiveMaxThemesChoice，其名称可能解释了它在将用户（Etudiant）限制为我正在构建的应用程序中最多选择5 themes的情况。这是我在EtudiantsChoixTheme Eloquent处注册选择的以下逻辑：

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;
use App\EtudiantsChoixTheme;

class fiveMaxThemesChoice implements Rule
{
    /**
     * Create a new rule instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        $choixEtudiants = EtudiantsChoixTheme::all();

            foreach ($choixEtudiants as $choixEtudiant) {
                  $IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id));
                if($IdEtudiantOccurences <= 5){
                    return true;
                }
                else{
                    return false;
                }
            }
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return 'You have already chosen a maximum of 5 themes.';
    }
}

当表中至少有1条记录时，此方法有效。 issue是当表为空时，即使表中还没有记录，也返回验证错误消息，因此没有最大值5（因此<= 5应该是正确的）。为什么这样不起作用？

我尝试了不同的语法：

$IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id)->first());

$IdEtudiantOccurences = $choixEtudiants->where('idEtudiant', auth()->user()->id)->first()->count();

$IdEtudiantOccurences = $choixEtudiants->where('idEtudiant', auth()->user()->id)->count();

表为空时，相同的问题仍然存在。有谁知道这里可能是什么问题？欢迎任何帮助或建议

Answer 1

<?php
declare(strict_types=1);

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;
use App\EtudiantsChoixTheme;

class FiveMaxThemesChoice implements Rule
{
    private const MAXIMUM_NUMBER_OF_THEMES = 5;

    public function passes($attribute, $value): bool
    {
        $etudiants = EtudiantsChoixTheme::where('idEtudiant', auth()->user()->id);

        return $etudiants->count() <= self::MAXIMUM_NUMBER_OF_THEMES;
    }

    public function message(): string
    {
        return 'You have already chosen a maximum of 5 themes.';
    }
}