Laravel many to many eloquent relationship tutorial example

In this tutorial, today we discuss about laravel many to many Eloquent relationship. Eloquent ORM means Object-relational Mapping and laravel provides a beautiful activerecord stucture. so we can easy to interact with application database. let’s start about many to many eloquent relationship.

Laravel many to many relationship is a complicated better than one to one and one to many relationships. Many-to-many relationship are returns the result of the belongsToMany data. For example, Many-to-many relationship such as one product can belong to multiple categories, and one category can have multiple products.

here, see below database stucture.

Categories

– id

– name

Products

– id

– title

category_product

– id

– category_id

– product_id

Setting Database Configuration

After complete installation of laravel. we have to database configuration. now we will open the .env file and change the database name, username, password in the .env file. See below changes in a .env file.

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=Enter_Your_Database_Name(many_to_many_relation)
DB_USERNAME=Enter_Your_Database_Username(root)
DB_PASSWORD=Enter_Your_Database_Password(root)

Create Table using migration

Now, We need to create a migration. so we will below command using create the categories, products and category_product table migration.

php artisan make:migration create_categories_table --create=categories
php artisan make:migration create_products_table --create=products
php artisan make:migration create_category_product_table --create=category_product

After complete migration. we need below changes in the database/migrations/create_categories_table, database/migrations/create_products_table and database/migrations/create_category_product_table file.

create_categories_table.php

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

create_products_table.php

<?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('title');
            $table->timestamps();
        });
    }
    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('products');
    }
}
?>

create_category_product_table.php

<?php
use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;
class CreateCategoryProductTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('category_product', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->integer('category_id')->unsigned();
            $table->integer('product_id')->unsigned();
			$table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
            $table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
            $table->timestamps();
        });
    }
    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('category_product');
    }
}
?>

Run the below command. after the changes above file.

php artisan migrate

Create Model

Here below command help through we will create the Category, Product and CategoryProduct model. we will also use “belongsToMany()” for a both model.

php artisan make:model Category
php artisan make:model Product 
php artisan make:model CategoryProduct

Category.php

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Category extends Model
{
    protected $fillable = [
        'name'
    ];
	
   /**
     * Get the products for the category.
     */
    public function products()
    {
	return $this->belongsToMany(Product::class,'category_product');
    }
}
?>

Product.php

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    /**
     * Get the category that owns the product.
     */
    public function categories()
    {
	return $this->belongsToMany(Category::class,'category_product');
    }
}

?>

CategoryProduct.php

<?php
 
namespace App;
 
use Illuminate\Database\Eloquent\Model;
 
class CategoryProduct extends Model
{
    //
}

?>

Route and Controller

We have to need put below code route in routes/web.

<?php
 
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/
 
Route::get('/', function () {
    return view('welcome');
});
 
Route::get('product','productsController@index');

?>

Here below command help to create the product controller.

php artisan make:controller ProductsController

ProductsController.php

<?php
namespace App\Http\Controllers;
use App\Product;
use App\Category;
use Illuminate\Http\Request;
class ProductsController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $product = Product::find(1);
        $category = Category::find(3);
	dd($product);
	dd($category);
    }

}
?>