Create foreign keys in laravel

2020_06_17_072617_asssign_products_foreign_keys.php

<?php

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

class AsssignProductsForeignKeys extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('prodcuts', function (Blueprint $table) {
            $table->unsignedInteger('category_id')->nullable();
            $table->foreign('category_id')->references('id')->on('categories');
        });

        Schema::table('prodcuts', function (Blueprint $table) {
            $table->unsignedInteger('type_id')->nullable();
            $table->foreign('type_id')->references('id')->on('types');
        });

        Schema::table('prodcuts', function (Blueprint $table) {
            $table->unsignedInteger('attribute_id')->nullable();
            $table->foreign('attribute_id')->references('id')->on('attributes');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        // DO NOT DROP TABLE HERE
        // ONLY, DELETE OR UPDATE COLUMNS HERE
    }
}