category migration

<?php

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

class CreateCategoriesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('categories', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->integer('parent_id')->nullable();
            $table->timestamps();
        });
    }

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

product migration

<?php

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

class CreateProductsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('products', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->string('image');
            $table->text('description');
            $table->text('characteristic');
            $table->timestamps();
        });
    }

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

tie table

<?php

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

class CreateProductsCategoryTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('category_products', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->integer('category_id')->unsigned();
            $table->integer('product_id')->unsigned();
            $table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
            $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');

        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('category_products', function (Blueprint $table) {
            $table->dropForeign('product_category_product_id_foreign');
            $table->dropForeign('product_category_category_id_foreign');
        });
        Schema::dropIfExists('category_products');
    }
}