In this tutorial, today we discuss about laravel hasManyThrough 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 hasManyThrough eloquent relationship.
Laravel hasManyThrough Eloquent relationship is woking with three tables of database. For example, The category is connected with products and products with orders, then we can access all orders connected with a specific category. categories have many products and products have many orders.
here, see below database stucture.
Categories
– id
– name
Products
– id
– category_id
– title
Orders
– 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(has_many_through_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 orders 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_orders_table --create=orders
After complete migration. we need below changes in the database/migrations/create_categories_table, database/migrations/create_products_table and database/migrations/create_orders_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->bigInteger('category_id')->unsigned();
$table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
$table->string('title');
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::dropIfExists('products');
}
}
?>
create_orders_table.php
<?php
use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;
class CreateOrdersTable extends Migration
{
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::create('orders', function (Blueprint $table) {
$table->bigIncrements('id');
$table->integer('product_id')->unsigned();
$table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::dropIfExists('orders');
}
}
?>
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 Order model. we will also use “hasManyThrough()” or relationship of both model.
php artisan make:model Category php artisan make:model Product php artisan make:model Order
Category.php
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Category extends Model
{
public function orders()
{
return $this->hasManyThrough(
'App\Order',
'App\Product',
'category_id', // Foreign key on products table...
'product_id', // Foreign key on orders table...
'id', // Local key on categories table...
'id' // Local key on products table...
);
}
}
?>
Product.php
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Product extends Model
{
//
}
?>
Order.php
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Order 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\Order;
use App\Category;
use Illuminate\Http\Request;
class ProductsController extends Controller
{
/**
* Display a listing of the resource.
*
* @return \Illuminate\Http\Response
*/
public function index()
{
$cate = Category::find(1);
$cateOrders = $cate->orders;
//dd($cateOrders);
}
}
?>