Filter results using 3 tables in Laravel 5.8?

Question

Create in controller a filter that takes data from 3 different tables. Below I put the relationship and an example of what needs to happen. I am not able to create in controller the filter that should take as reference 02 parameters that will be passed in the URL according to the user’s choice. What’s Working: When I register a Course, I put the Area of Expertise and the Category, this is working and saving well in DB.

Now what I need to do is: On the site, I have a menu that takes the Categories and a submenu that lists the Areas. Type: I stop the mouse in Graduate School and list all the areas it has. I want to filter in the view of courses only those that are Graduate and Area that he clicked.

The URL would look like this in the case, example

http://localhost/SiteNovo/public/pos-graduacao/saude

Relationships are like that:

And mine controller are like this for now:

public function cursos($categoria, $area){

    $cursos = Curso::all();
    $categorias = CategoriaCurso::all();
    $areas = AtuacaoArea::all();

    //Filtrar cursos

    return view('site.cursos.cursos',compact('cursos'));
}

Answer 1

In the method cursos class SiteController must have the following signature:

class SiteController extends Controller 
{
     public function cursos($id_categoria_curso, $id_atuacao_area)
     {

     }
}

this will solve your recovery, but be careful with the returned values and criticize them to see if the data really is of the expected type (validate data).

---

If by any chance these two parameters are of type number can use the restriction part on the route (Regular Expression Constraints), then in your route configuration do:

Route::get('/cursos/{id_categoria_curso}/{id_atuacao_area}', 'SiteController@cursos')
     ->name('cursos')
     ->where(['id_categoria_curso' => '[0-9]+', 'id_atuacao_area' => '[0-9]+']);

---

Other examples of route restriction:

Text restriction:

Route::get('user/{name}', function ($name) {
    //
})->where('name', '[A-Za-z]+');

Number restriction:

Route::get('user/{id}', function ($id) {
    //
})->where('id', '[0-9]+');

Restriction set:

Route::get('user/{id}/{name}', function ($id, $name) {
    //
})->where(['id' => '[0-9]+', 'name' => '[a-z]+']);

^{Reference:Laravel - Regular Expression Constraints}

To filter the courses with Eloquent:

class SiteController extends Controller 
{
     public function cursos($id_categoria_curso, $id_atuacao_area)
     {
          $cursos = Curso::where('id_categoria_curso', $id_categoria_curso)
              ->where('id_atuacao_area', $id_atuacao_area)
              ->get();
     }
}

In the documentation of Eloquent Builder has the various ways to filter fields from a table, sort and so on.