laracom/database/migrations/2016_05_26_051502_create_cities_table.php

<?php

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

class CreateCitiesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('cities', function (Blueprint $table) {
            $table->string('name');
            $table->string('state_code')->nullable();
            $table->integer('province_id')->unsigned()->nullable();
            $table->foreign('province_id')->references('id')->on('provinces');
        });
    }

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