Searching data of laravel meta table of type metable

I have 3 tables users, articles and metas. I had defined the morphTo() and morphToMany() according to the laravel 5.3 doc and I can pull any particular property of either the user or article defined in the metas table such as firstname or lastname or coordinate.

Now am having difficulties writing the correct model to search these properties e.g a search for any user's firstname or lastname or both.

<u>User table</u>
id.    username.    password
1.      Test.             Testpass

<u>article</>
id.   Title.                     Slug
1.     My article title.   my-article-title

Metas table

Id.     key.                value.                 metable_id    metable_type
1       firstname      Ade                     1                      App\User
2.      content.        Sample article   1.                     App\Article
3.      lastname.     Keon.                   1.                    App\User

Meta.php extract

public function metable() {
    return $this->morphTo();
}

User.php extract

public function meta() {
    return $this->morphToMany('App\User', 'metable');
}

public function getName() {
     $user = User::find($this->id);
     $metadata = $user->meta()->whereIn('key', ['firstname', 'lastname']) ;
     dd($metadata);
}

Article.php extract

public function meta() {
    return $this->morphToMany('App\User', 'metable');
}

The getName function worked as expected but I can't figure out how to do a search of the user metadata unlike the conventional php/mysql table joins

Dont know how as the whole polymorphic relationship in laravel is new to me but I found and used something like these:

public function getSearch() {
      return User::with(array('metas' => function($query) { 
            $query->where('value', $query); 
      }));
 }

or

public function getSearch() {
         return User::with('metas') 
         ->whereHas('metas', function($query) { 
                $query->where('value', '=', $query); 
          });
   }

I cant see or reason how to join the tables in laravel

here is my new search query

public function getResults(Request $request) {
    $keyword = $request->input('query');
    $filterOne = $request->input('minAge');
    $filterTwo = $request->input('maxAge');

    $query = User::with(['meta' => function ($q) {
        $q->where('value', 'like', $keyword)
            ->orWhere(function ($q) {
                $q->whereBetween('value', [$filterOne,$filtertwo]);
            });
    }])->get();

dd($query);
}

Thanks for the contribution above, the insufficient of this actually push me harder to readings and thinking, I finally came across the use() with function query as shown below;

public function getResults(Request $request) {
        $keyword = $request->input('query');
        $filterOne = $request->input('minAge');
        $filterTwo = $request->input('maxAge');

        if (isset($keyword)) {
            $query = User::with(['meta' => function ($q) use ($keyword,$filterOne,$filterTwo) {
                $q->where('value', 'LIKE', $keyword)
                    ->whereBetween('value', [$filterOne, $filterTwo]);
            }])->get();
        } else {
            $query = User::with(['meta' => function ($q) use ($filterOne,$filterTwo) {
                $q->whereBetween('value', [$filterOne, $filterTwo]);
            }])->get();
        }

        dd($query);
    }

This gives me the result am looking for; though am not sure the effect on performance when dealing with large dataset but then i guess that's my next assignment.