Answers for "how begin primary key from 1000 laravel migration"

laravel migration with primary key

$table->string('code', 30)->primary();

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');
});