Answers for "migrate larevel 8"

re migrate laravel

Try:
composer dump-autoload
php artisan config:cache

If not working also try:
php artisan migrate:refresh.

laravel 8 foreign key migration

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

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});