Laravel HasManyThrough 深厚的关系

Question

I have a multi-tenant setup where a tenant HasMany workspaces and a workspace BelongsToMany students. How do I create a relationship from the tenant where I retrieve all the students from all workspaces within the tenant?

I've took a look at hasManyThrough but that does not solve the problem. Right now I have this function:

public function getStudents()
{
    $this->workspaces()->get()->map(function ($workspace) {
        return $workspace->students;
    })->flatten()->unique();
}

But I'd like to do it in a relation instead of the above code. Any advice?

Tenant :HasMany=> Workspace(tenant_id) :BelongsToMany=> Student(student_workspace table)

Thanks in advance!

Answer 1

You could do it through join like:

public function students(){
    return Student::select('students.*')
        ->join('student_workspace', 'students.id', '=', 'student_workspace.student_id')
        ->join('workspaces', 'workspaces.id', '=', 'student_workspace.workspace_id')
        ->join('tenants', 'tenants.id', '=', 'workspaces.tenant_id')
        ->where('tenants.id', $this->id);
}

Or like any normal relation using this package: hasManyDeep through the following steps:

First:

composer require staudenmeir/eloquent-has-many-deep

In your Workspace model file:

public function students()
{
    return $this->belongsToMany(Student::class, 'student_workspace');
}

In your Tenant model file:

use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

class Tenant extends Model
{

    use HasFactory, HasRelationships;

    public function students(){
        return $this->hasManyDeepFromRelations($this->workspaces(), (new Workspace)->students());
    }

}

Hope this would be helpful.