CODEWITHSUNDEEP
phplaravel
Carlo-Hein Versfeld
Carlo-Hein Versfeld

Reputation: 33

hasMany with default in Laravel

In Laravel - Is there a way to return a diffent collection if a relationship does not return any values?

Eg.

class Topic 
{
    public function questions()
    {
        return $this->hasMany(Questions::class);
    }
}

This return the questions for the topic. But the required behaviour I need is if I query $topic->questions() is for it to return me a list of

return Questions::get()->whereNull('topic_id')

Anyone know how I can accomplish this?

The migrations:

Schema::create('topics', function (Blueprint $table) {
    $table->increments('id');
    $table->string('topic')->index();
    $table->timestamps();
});

Schema::create('questions', function (Blueprint $table) {
    $table->id();

    $table->unsignedBigInteger('topic_id')
        ->nulluble()
        ->comment('link to the topic table');
    $table->foreign('topic_id', 'fk_topic_question')
        ->references('id')
        ->on('topics')
        ->onDelete('cascade');

    $table->string('question')->nullable();

    $table->timestamps();
});

And then default questions seed example:

$data = [
    [
        'question'=>'default questions 1'
    ],
    [
        'question'=>'default questions 2'
    ]
];

Questions::insert($data);

Upvotes: 0

Views: 1870

Answers (2)

Carlo-Hein Versfeld
Carlo-Hein Versfeld

Reputation: 33

I settled on a interim solution (bit hacky but does what I need) :

public function getQuestions()
    {
        if ($this->questions()->exists()) {
            return $this->questions;
        } else {
            return Question::all();
        }
    }

then I use $topic->getQuestions() instead of $topic->questions()

Upvotes: 0

Saman
Saman

Reputation: 2656

You can use optional helper function: https://laravel.com/docs/8.x/helpers#method-optional

create a topic for default questions and relate defualt questions to this topic and then you can use this:

$questions = optional($preferTopic,$defaultTopic)->questions;

Upvotes: 1

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