query

                    SELECT * FROM posts 

                            WHERE is_published == 1 AND (category = 'Laravel' OR viewer > 50)
                    

using model

                    $posts = Post::select("*")
                        ->where("is_published", 1)
                        ->where(function($query) {
                                $query->where('category', 'Laravel')
                                      ->orWhere('viewer', '>', 100);
                            })
                        ->get();

                          

query

                          SELECT * FROM posts 

                              WHERE viewer > 100 OR (category = 'Laravel' AND viewer > 50)
                          

using model

                          $posts = Post::select("*")
                        ->where("viewer", ">", 100)
                        ->orWhere(function($query) {
                                $query->where('category', 'Laravel')
                                      ->where('viewer', '>', 50);
                            })
                        ->get();