osb/database/migrations/0051-create_site_details.php

<?php

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

return new class extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
		Schema::create('site_details', function (Blueprint $table)
		{
			$table->string('key');
			$table->string('value');

			$table->integer('site_id')->unsigned();
			$table->foreign('site_id')->references('id')->on('sites');

			$table->unique(['site_id','key']);
		});
    }

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