BookStack/database/migrations/2017_01_01_130541_create_comments_table.php

<?php

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

class CreateCommentsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('comments', function (Blueprint $table) {
            $table->increments('id')->unsigned();                       
            $table->integer('page_id')->unsigned();
            $table->longText('text')->nullable();
            $table->longText('html')->nullable();
            $table->integer('parent_id')->unsigned()->nullable();
            $table->integer('created_by')->unsigned();
            $table->integer('updated_by')->unsigned()->nullable();
            $table->index(['page_id', 'parent_id']);
            $table->timestamps();
        });
    }

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