Top Laravel Interview Questions and Answers

Database migration is like the version control of the database, which allows the team to modify and share the database schema of the application. Database migrations are paired with the schema builder of Laravel which is used to build the database schema of the application.

It is a type of version control for our database. It is allowing us to modify and share the application's database schema easily.

A migration file contains two methods up() and down().

up() is used to add new tables, columns, or indexes database, and the down() is used to reverse the operations performed by the up method.

You can generate a migration & its file with the help of make:migration

Syntax : php artisan make:migration blog

A current_date_blog.php file will be created in database/migrations.

The "env" file in Laravel is a central configuration file that allows developers to define and manage environment-specific settings for their applications. It provides flexibility and adaptability to your Laravel project across different environments, like local development, staging, and production. You can store sensitive information like database credentials, API keys, and other settings in an "env" file. You can access these variables using the env helper or the Config facade.

Simply put, the "env" file in Laravel provides a flexible and secure method to manage environment-specific configurations by defining variables. Moreover, configuration enhances your application's security and promotes collaboration among team members by providing a centralized location to manage and share configuration settings.

In between head, tag put <meta name="csrf-token" content="{{ csrf_token() }}"> and in Ajax, we have to add
$.ajaxSetup({
   headers: {
     'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
   }
});

Service providers are the fundamentals of bootstrapping laravel applications. All the core services of Laravel are bootstrapped through service providers.

These powerful tools are used by developers to manage class dependencies and perform dependency injection. To create a service provider, we have to use the below-mentioned artisan command.

You can use php artisan make: provider ClientsServiceProvider artisan command to generate a service provider :

It has the below listed functions in its file.

• register function
• boot function

Follow these steps to successfully create a package in Laravel:

• Creating a Folder Structure
• Creating the Composer File
• Loading the Package from the Main Composer.JSON File
• Creating a Service Provider for Package
• Creating the Migration
• Creating the Model for the Table
• Creating a Controller
• Creating a Routes File
• Creating the Views
• Updating the Service Provider to Load the Package
• Update the Composer File

In Laravel, we can use whereBetween() function to get data between two dates.

We can add that particular URL or Route in $except variable. It is present in the app\Http\Middleware\VerifyCsrfToken.php file.

It acts as a middleman between a request and a response. Middleware is a type of filtering mechanism used in Laravel application.

• We can create middleware with
  php artisan make:middleware UsersMiddleware
• Here "UsersMiddleware" is the name of Middleware. After this command, a "UsersMiddleware.php" file is created in app/Http/Middleware directory.
• After that we have to register that middleware in kernel.php (available in app/Http directory) file in "$routeMiddleware" variable.
  'Users' => \App\Http\Middleware\UsersMiddleware::class,
• Now we can call "Users" middleware where we need it like controller or route file.
• We can use it in a controller file like this.
  public function __construct() {
   $this->middleware('Users');
}
• In route file we can use like this.
  Route::group(['middleware' => 'Users'], function () {
   Route::get('/', 'HomeController@index');
});

How to create a Stored Procedure

To create a Stored Procedure you can execute given code in your MySQL query builder directly or use phpmyadmin for this.

DROP PROCEDURE IF EXISTS `get_subcategory_by_catid`;
delimiter ;;
CREATE PROCEDURE `get_subcategory_by_catid` (IN idx int)
BEGIN
SELECT id, parent_id, title, slug, created_at FROM category WHERE parent_id = idx AND status = 1 ORDER BY title;
END
;;
delimiter ;

After this, you can use this created procedure in your code in Laravel.

How to use stored procedure in Laravel

$getSubCategories = DB::select(
   'CALL get_subcategory_by_catid('.$item->category_id.')'
);

The facade gives the “static” interface to all the classes available in the service container of the application. Laravel comes along with many interfaces that provide the access to almost all the features of Laravel.

All the facades are defined in the namespace Illuminate\Support\Facades for easy accessibility and usability.