accessing inverse hasmany in controller laravel - laravel

Question

I have three tables topics, category(HowtoCategory::class), sections(Howto::class).
Multiple categories belong to one topic and multiple sections belong to one category.
Topic Has Many Category
Category Has Many Sections
Category Belongs to Topic
Sections Belongs To Category
Topic Has Many Sections Through Category
I want to search through the sections(Howto::class) but display the related topics. How can I access topics in the controller from my query search of sections? I dont want to access it in the view but in the controller.
Controller
public function index(Request $request)
{
if (request()->filled('search')) {
request()->fullUrlWithQuery(['search ' => null]);
$sections = Howto::search($request->search)->get();
$request = $request->input('search');
} else {
$sections = null;
}
return view('howto-pages.howto-main', [
'sections' => $sections,
]);
}
Models
class Topic extends Model
{
public function categories()
{
return $this->hasMany(HowtoCategory::class);
}
public function sections()
{
return $this->hasManyThrough(Howto::class, HowtoCategory::class);
}
}
class HowtoCategory extends Model
{
public function sections()
{
return $this->hasMany(Howto::class);
}
public function topic()
{
return $this->belongsTo(Topic::class);
}
}
class Howto extends Model
{
public function category()
{
return $this->belongsTo(HowtoCategory::class);
}
}
Tables
mysql> desc howto;
+-------------------+-----------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+-----------------+------+-----+---------+----------------+
| id | bigint unsigned | NO | PRI | NULL | auto_increment |
| title | varchar(255) | NO | | NULL | |
| body | mediumtext | YES | | NULL | |
| description | mediumtext | YES | | NULL | |
| created_at | timestamp | YES | | NULL | |
| updated_at | timestamp | YES | | NULL | |
| section_id | int | YES | | NULL | |
| howto_category_id | bigint unsigned | YES | MUL | NULL | |
+-------------------+-----------------+------+-----+---------+----------------+
mysql> desc howto_category;
+----------------------+-----------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+-----------------+------+-----+---------+----------------+
| id | bigint unsigned | NO | PRI | NULL | auto_increment |
| howto_category_title | varchar(255) | NO | | NULL | |
| icon | varchar(255) | YES | | NULL | |
| description | mediumtext | YES | | NULL | |
| intro | text | YES | | NULL | |
| category_id | int | YES | | NULL | |
| created_at | timestamp | YES | | NULL | |
| updated_at | timestamp | YES | | NULL | |
| topic_id | bigint unsigned | YES | MUL | NULL | |
+----------------------+-----------------+------+-----+---------+----------------+
mysql> desc topics;
+-------------+-----------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-----------------+------+-----+---------+----------------+
| id | bigint unsigned | NO | PRI | NULL | auto_increment |
| topic_title | varchar(255) | NO | | NULL | |
| description | mediumtext | YES | | NULL | |
| created_at | timestamp | YES | | NULL | |
| updated_at | timestamp | YES | | NULL | |
+-------------+-----------------+------+-----+---------+----------------+

Answer 1

First and foremost i'd define the foreignIDS in the relations just to make sure that are working as expected.
class Topic extends Model
{
public function categories()
{
return $this->hasMany(HowtoCategory::class);
}
public function sections()
{
return $this->hasManyThrough(
Howto::class, HowtoCategory::class,
"topic_id", "howto_category_id"
);
}
}
then you can get the Topics by searching the sections like so
use Illuminate\Database\Eloquent\Builder;
$topics = Topic::whereHas("sections", function(Builder $query) {
$query->where("howto.description", "something to search")
})->get();