How to arrange relationships with such a Laravel table?

Question

Laravel

There are three models:

1. Event
   
2. Subject
   
3. Speaker
   

It is necessary to organize the following logic: an event can contain several topics, each topic contains several speakers. All this must be placed in a database table in this form:

event_id | topic_id | speaker_id
    1    |    1     |    1    
    1    |    1     |    2
    1    |    2     |    5
    2    |    1     |    3

Can you please tell me how best to organize this without changing the structure of the table?

Answer 1

Add the event_id row to the topic table Add the topic_id row to the
speaker table Add the topic_id row to
the event model

public function topic()
    {
        return $this->hasMany(Topic::class, 'event_id', 'event_id');
    }

To the topic model

public function event(): BelongsTo
    {
        return $this->belongsTo(Event::class, 'event_id', 'event_id');
    }
    public function speaker()
    {
        return $this->hasMany(Speaker::class, 'topic_id', 'topic_id');
    }

speaker model

public function topic(): BelongsTo
    {
        return $this->belongsTo(Topic::class, 'topic_id', 'topic_id');
    }