How to structure this relation?

@ranx99 So here you need to check with every model before retrieving. I think create one to one model relationship and pass a string along with the input. so based on string it will go and display into that model.

That would be a polymorphic relationship :)

https://laravel.com/docs/master/eloquent-relationships#polymorphic-relationships

One way would be to have a custom attribute that handles this logic for you. Eg.

public function getContentAttribute()
{
    if ($this->type === 'video') {
        return $this->video;
    } else if ($this->type  === 'article') {
        return $this->article;
    }
}

And then have a relation for each (they can use the same column in the lesson table if needed.. Eg.

public function video()
{
    return $this->hasOne(Video::class, 'id', 'content_id');
    }
}

+1 for @ftiersch :)

First would be polymorphic relationship. One to one or one to many. https://laravel.com/docs/5.8/eloquent-relationships#polymorphic-relationships

Your lesson table could have two columns beside the usual ones. (following the naming convention)

• contentable_id
• contentable_type

For storing not just the ID of the model, but the type.

So, I would use the polymorphic relationship like this:

After adding this line to lessons table:

$table->morphs('taggable');

then my model will be like:

class Lesson extends Model
{
    public function contentable()
    {
        return $this->morphTo('contentable');
    }
}

How can I save a Video, Article or an Audio to the lesson?

Or you could skip polymorphic and just use radio buttons to select one of the four types.

Not the same but similar to selecting a male or a female with radio buttons.

It's either one or the other.