Laravel model save() сохранит дублированные данные в db

create a db table named questions and a model named Question.

Прочтите об определении моделей здесь

Из вашего интерфейса командной строки:

php artisan make:model Question --migration

Отредактируйте модель вопроса:

<?php 

namespace App;

use Illuminate\Database\Eloquent\Model;

class Question extends Model
{
    // Just tweak this for whatever your Model looks like 
    protected $fillable = [
        'subject',
        'body',
        'author'
    ];

}

Отредактируйте миграцию create_questions_table:

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateQuestionsTable extends Migration
{

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('questions', function (Blueprint $table) {
            $table->increments('id');
            $table->string('body');
            $table->string('subject');
            $table->string('author');
            $table->timestamps();
        });
     }


    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('questions');
    }

}

Из вашего CLI запустите php artisan migrate

add a function to save data into db.

Ознакомьтесь с Документы Laravel о контроллерах и о том, что вы можете с ними делать.

Снова из вашего CLI:

php artisan make:controller QuestionController

ВопросКонтроллер:

<?php

namespace App\Http\Controllers;
use App\Question;
use Illuminate\Http\Request;

class QuestionController extends Controller {

    public function store( Request $request )
    {

        // Create a new instance of your Question Model
        //modify input param .
        $question = App\Question::firstOrNew([
            'body' => $request->body,
            'subject' => $request->subject,
            'author' => $request->author
        ]);

        // Then save it to the database
        $question->save();

        return back()->with('success', 'Question posted');

    }

}

Вопрос.blade.php

<form method = "POST" action = "/question">
    @csrf 
    <input type = "text" name = "body" id = "body" class = "form-control">
    <input type = "text" name = "subject" id = "subject" class = "form-control">
    <input type = "text" name = "author" id = "author" class = "form-control">
    <button class = "btn btn-primary">Ask Question</button>
</form>

@if ( session('success') )
    <div class = "alert alert-success">
        <h3>Question asked!</h3>
    </div>
@endif 

Маршруты/web.php

Route::post('/question', QuestionController@store)->name('ask-question');