Iterating over joined query data in Laravel Lumen

Categories and courses are two tables. Based on Category, an 'n' number of data can be inserted into the course. While fetching the API response, it should be like below.

Controller

public function catlist($catid)
{
    $category = 
    DB::table('courses')
    ->join('categories', 'courses.category_id', '=', 'categories.id')// joining the Categories table , where category_id and categories id are same
    ->select(
    'categories.id as catid',
    'categories.name as catname',
    'courses.id as courseid',
    'courses.title as coursename'
    )
    ->where('courses.category_id', '=', $catid)
    ->get();

    foreach ($category as $cat) 
    {
        $data = [
            'category'=>[
                "id" => $cat->catid,
                "name" => $cat->catname,
                ],
            'courselist'=>[
                "id" => $cat->courseid,
                "name" => $cat->coursename,
            ]
        ];
    }
    return response()->json([
        'success' => true,
        'data' => $data,
    ],200);
} 

The actual result is:

  "data": {
    "category": {
        "id": 1,
        "name": "Test Category"
    },

    "courseList": {
        "id": 2,
        "title": "Course 2"
    }
}

Expected results will be:

data=[
    category: {
      id: 1,
      name: "Test Category"
      },

      courseList: [
      {
        id: 1,
        title: "Course 1",
      },
      {
        id: 2,
        title: "Course 2",
      },
    ],
]

I found myself after doing a lot of search. Now it is working now.

   $category = DB::table('categories')->where('id', $catid)->first();
    // Retrieve course list
    $courseList = DB::table('courses')->whereIn('category_id', [$catid])->get();

    if ($category === null) 
    {
        return response()->json([
            'success' => false,
            'message' => 'No such a Category',
        ], 404);
    }else{
        // Construct the response array
        $data = [
            'category' => $category,
            'courseList' => $courseList,
        ];
    
        return response()->json([
            'success' => true,
            'data' => $data,
        ],200);
    }