在Laravel中如何选择表中的所有列名？

CREATE TABLE students(
   id            INTEGER       NOT NULL    PRIMARY KEY,
   name          VARCHAR(10)   NOT NULL,
   email         VARCHAR(15)   NOT NULL,
   created_at    VARCHAR(27)   NOT NULL,
   updated_at    VARCHAR(27)   NOT NULL,
   address       VARCHAR(3)    NOT NULL
);

mysql> desc students; 
+------------+-------------+------+-----+---------+-------+ 
| Field      | Type        | Null | Key | Default | Extra | 
+------------+-------------+------+-----+---------+-------+ 
| id         | int         | NO   | PRI | NULL    |       | 
| name       | varchar(15) | NO   |     | NULL    |       | 
| email      | varchar(20) | NO   |     | NULL    |       | 
| created_at | varchar(27) | YES  |     | NULL    |       | 
| updated_at | varchar(27) | YES  |     | NULL    |       | 
| address    | varchar(30) | NO   |     | NULL    |       | 
| age        | int         | YES  |     | NULL    |       | 
+------------+-------------+------+-----+---------+-------+ 
7 rows in set (0.08 sec)

use Illuminate\Support\Facades\Schema;

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Schema;

class StudentController extends Controller {
   public function index() {
      $columns = Schema::getColumnListing('students');
      print_r($columns);
   }
}

Array(
   [0] => id
   [1] => name
   [2] => email
   [3] => created_at
   [4] => updated_at
   [5] => address
)

<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Student extends Model {
   use HasFactory;
   protected $fillable = ['name','email','address'];
}

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Models\Student;

class StudentController extends Controller {
   public function index() {
      $student = Student::first();
      $table_columns = array_keys(json_decode($student, true));
      print_r($table_columns);
   }
}

Array(
   [0] => id
   [1] => name
   [2] => email
   [3] => created_at
   [4] => updated_at
   [5] => address
)

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use DB;

class StudentController extends Controller {
   public function index() {
      $table = DB::table('students')->get();
      $cols = array_keys(json_decode(json_encode($table[0]), true));
      print_r($cols);
   }
}

Array ( 
   [0] => id 
   [1] => name 
   [2] => email 
   [3] => created_at 
   [4] => updated_at 
   [5] => address
)

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use DB;

class StudentController extends Controller {
   public function index() {
      $columns_names = [];
      $tableDet = DB::select("SHOW COLUMNS FROM students");
      foreach($tableDet as $column) {
         $columns_names[$column->Field] = '';
      }
      print_r($columns_names);
   }
}

Array ( 
   [id] => 
   [name] => 
   [email] => 
   [created_at] => 
   [updated_at] => 
   [address] => 
)