Top 50 Laravel Interview Questions and Answers
Laravel is a PHP web framework launched by Taylor Otwell. It is a free and open-source framework that is designed to develop web applications with MVC (model-view-controller). Stay tuned for the latest advancements and best Laravel Interview Questions. It is based on Symfony and its source is GitHub licensed under MIT license terms. Released in the year 2011, it is featured as a modular packaging system.
Quick Facts About Laravel | |
---|---|
What is the latest version of Laravel? | 10.0, released on February 14th, 2023. |
When was Laravel first released? | June 2011. |
Laravel is Created By | Taylor Otwell |
What language does Laravel use? | PHP |
Which is the best IDE for Laravel? | Netbeans, PhpStorm, Atom, Sublime Text |
Top 20 Laravel Interview Questions and Answers (2023)
- What is Laravel and how does it differ from other PHP frameworks?
- What are the key features of Laravel?
- What is the importance of Composer in Laravel?
- What are Service Providers and how do they work in Laravel?
- What is the purpose of Facades in Laravel?
- What is the difference between Eloquent and Query Builder in Laravel?
- What is a Middleware in Laravel and how is it used?
- What is the purpose of Artisan in Laravel and how is it used?
- What is the difference between a Repository and a Service in Laravel?
- How do you implement caching in Laravel?
- How do you handle errors and exceptions in Laravel?
- What is a Service Container in Laravel and how is it used?
- How do you implement Authentication and Authorization in Laravel?
- What are Laravel Contracts and how are they used?
- How do you create and use Events and Listeners in Laravel?
- What is the purpose of Queues in Laravel and how are they implemented?
- How do you implement Localization in Laravel?
- What is a Trait in Laravel and how is it used?
- What is the difference between CSRF and XSS attacks in Laravel?
- How do you optimize the performance of a Laravel application?
Laravel Interview Questions for Job Seekers and Hiring Managers
Laravel is a popular open-source PHP web application framework that follows the MVC architectural pattern. It was created by Taylor Otwell in 2011 and has gained a large and active community of developers.
Laravel is known for its elegant syntax, robust features, and developer-friendly approach. It offers a wide range of features out of the box, including routing, middleware, authentication, templating, and database migration tools. Additionally, Laravel has a modular structure that allows developers to pick and choose the components they need for their specific project, making it highly customizable. One of the key features of Laravel is its object-relational mapping (ORM) system, which makes it easy to work with databases by allowing developers to interact with database tables using PHP classes. Laravel's ORM, called Eloquent, simplifies creating, retrieving, updating, and deleting records from a database.
Another unique feature of Laravel is its built-in support for unit testing and integration testing, making it easy to ensure that your code functions correctly and that new features or changes do not break existing functionality. Compared to other PHP frameworks, Laravel is often praised for its clean and expressive syntax, which makes it easier for developers to write and read code. Laravel also strongly focuses on developer experience, offering a powerful command-line interface (CLI) called Artisan, which provides many helpful tools for managing a Laravel application.
Overall, Laravel's elegant syntax, robust features, and developer-friendly approach make it a popular choice for building web applications in PHP.
Composer is a dependency manager for PHP widely used in the PHP community, including the Laravel framework. Composer allows developers to declare the libraries and packages their projects depend on, and it manages the installation and updating of those dependencies.
- The importance of Composer in Laravel is significant because Laravel itself and most of its third-party packages rely on Composer for installation and management.
- Composer simplifies installing and updating dependencies, reducing the time and effort required to manage a Laravel project's dependencies.
- Composer manages dependencies for the framework itself and any packages or libraries that a developer may use in their Laravel project.
- The composer.json file is used to declare dependencies and the composer.lock file is generated to ensure that everyone working on the project uses the same dependencies versions.
The composer plays a crucial role in the Laravel ecosystem by simplifying dependency management, reducing the risk of version conflicts, and streamlining the development process.
You can create a constants.php page in the config folder if does not exist. Now you can put a constant variable with value here and can use it with
Config::get('constants.VaribleName');
return [
'ADMINEMAIL' => '[email protected]',
];
Now we can display with
Config::get('constants.ADMINEMAIL');
Our first step should be
DB::connection()->enableQueryLog();
After our query, it should be placed
$querieslog = DB::getQueryLog();
After that, it should be placed
dd($querieslog)
DB::connection()->enableQueryLog();
$result = Blog:where(['status' => 1])->get();
$log = DB::getQueryLog();
dd($log);
Laravel, a popular PHP web application framework, provides a built-in queueing system that allows developers to defer the processing of time-consuming tasks, such as sending emails or processing large amounts of data, to a later time.
Here's a brief overview of how Laravel implements queueing and job scheduling:
- Laravel uses different queue drivers, such as Redis, Beanstalkd, Amazon SQS, and databases, to manage the queue of jobs. Each driver provides a different implementation, but they all follow the same basic principle of pushing jobs into a queue and popping them off when they're ready to be processed.
- To create a job in Laravel, use the make: job Artisan command or create a new class that extends the Illuminate\Queue\Jobs\Job class. A job class typically defines a handle() method that contains the logic to be executed when the job is processed.
- Once a job is created, it can be dispatched to the queue using the dispatch() or dispatchNow() methods. The former method puts the job onto the queue, while the latter method executes the job immediately without queueing it.
- Laravel provides a simple interface for scheduling jobs using the Illuminate\Console\Scheduling\Schedule class. You can define a schedule by chaining methods to specify when a job should run, such as daily() or hourly(), and then use the run() method to specify the job to be executed.
- Laravel also provides a convenient way to monitor the status of jobs and queues using the php artisan queue: work command, which starts a worker process that listens for new jobs and processes them as they become available. You can also use the php artisan queue: failed command to view and manage failed jobs.
Overall, Laravel's queueing system is a powerful and flexible way to handle time-consuming tasks in a web application. Its simple interface makes it easy to use and customize for your needs.
Middleware in laravel works as a platform among the request and the response. It provides the mechanism for investigating the HTTP requests which are entering into your application. For instance, middleware in laravel ensures that the user of your particular application is authenticated. If they found that the user is not authenticated, it will redirect the user to the main login page of the application.
Example: If a user is not authenticated and it is trying to access the dashboard then, the middleware will redirect that user to the login page.
In Laravel, {{ $username }} and {!! $username !!} displays dynamic content within a Blade template. However, they have different behaviors depending on the context in which they are used.
{{ $username }} is used to display escaped output. This means that any special characters in the variable's value, such as HTML tags or JavaScript code, will be converted to their corresponding HTML entities to prevent them from being interpreted as code. This is done to help prevent cross-site scripting (XSS) attacks, where malicious code is injected into a web page.
{!! $username !!} is used to display unescaped output. This means the variable's value will be displayed exactly as it is, without any special characters being converted to HTML entities. This is useful when displaying HTML markup or other special characters.
However, using unescaped output can be risky, especially if the variable's value comes from user input. It can make your application vulnerable to XSS attacks. Therefore, you should always sanitize user input before displaying it on a web page and use the escaped output ({{ $variable }}) by default unless you have a good reason to use the unescaped output ({!! $variable !!}).
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.
Why Laravel Is the Best PHP Framework 2023?
Laravel is believed to be a very adaptable application creation PHP framework. This is due in large part to the features of Laravel that include two-way binding of data as well as quick and easy transitions, unit testing integration with messaging applications, as well as many other features.
- Easy Installation
- Database Migration
- Supports MVC Architecture
- Traffic Management
- Robust Security Features
- Modular Design
- Object-Oriented Libraries
- Cloud Storage Option
- Host of Libraries
Reverse routing in the laravel means the process that is used to generate the URLs which are based on the names or symbols. URLs are being generated based on their route declarations.
With the use of reverse routing, the application becomes more flexible and provides a better interface to the developer for writing cleaner codes in the View.
NOTE: If you want to read more about WordPress Interview Questions then you can visit here.
Route:: get(‘list’, ‘[email protected]’);
{{ HTML::link_to_action('[email protected]') }}
In between head, tag put <meta name="csrf-token" content="{{ csrf_token() }}"> and in Ajax, we have to add
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
}
});
Service providers are the fundamentals of bootstrapping laravel applications. All the core services of Laravel are bootstrapped through service providers.
These powerful tools are used by developers to manage class dependencies and perform dependency injection. To create a service provider, we have to use the below-mentioned artisan command.
You can use php artisan make: provider ClientsServiceProvider
artisan command to generate a service provider :
It has the below listed functions in its file.
- register function
- boot function
Follow these steps to successfully create a package in Laravel:
- Creating a Folder Structure
- Creating the Composer File
- Loading the Package from the Main Composer.JSON File
- Creating a Service Provider for Package
- Creating the Migration
- Creating the Model for the Table
- Creating a Controller
- Creating a Routes File
- Creating the Views
- Updating the Service Provider to Load the Package
- Update the Composer File
In Laravel, we can use whereBetween()
function to get data between two dates.
Users::whereBetween('created_at', [$firstDate, $secondDate])->get();
We can add that particular URL or Route in $except variable. It is present in the app\Http\Middleware\VerifyCsrfToken.php
file.
class VerifyCsrfToken extends BaseVerifier {
protected $except = [
'Pass here your URL',
];
}
It acts as a middleman between a request and a response. Middleware is a type of filtering mechanism used in Laravel application.
- We can create middleware with
php artisan make:middleware UsersMiddleware
- Here "UsersMiddleware" is the name of Middleware. After this command, a "UsersMiddleware.php" file is created in app/Http/Middleware directory.
- After that we have to register that middleware in kernel.php (available in app/Http directory) file in "$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('/', '[email protected]');
});
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.
use Illuminate\Support\Facades\Cache;
Route::get('/cache', function () {
return Cache::get('PutkeyNameHere');
});
It is a helper function which is used to dump a variable's contents to the browser and stop the further script execution. It stands for Dump and Die.
dd($array);
We can create a helper file using Composer. Steps are given below:-
- Please create a app/helpers.php file that is in app folder.
- Add
"files": [
"app/helpers.php"
]
in "autoload" variable. - Now update your composer.json with composer dump-autoload or composer update
Here are some of the reasons why Laravel is considered to be better than CodeIgniter:
Laravel | CodeIgniter |
---|---|
It supports Eloquent object-relational mapping ORM. | It does not support ORM. |
It has in-built modularity features. | It requires users to create and maintain modules using Modular Extension. |
It is straightforward to perform Database Schema Migration. | There are no particular features to simplify Database Schema Migration. |
It provides an in-built template engine, called Blade. | It does not provide an in-built template engine. |
It is easier to develop REST API. | Developing REST API is complicated. |
Allows developers to establish custom HTTP Routes. | It does not support HTTP Routes completely. |
NOTE: If you are looking CodeIgniter Questions for interview preparations, then you can visit here.
Laravel installation steps:-
- Download composer from https://getcomposer.org/download (if you don’t have a composer on your system)
- Open cmd
- Goto your htdocs folder.
- C:\xampp\htdocs>composer create-project laravel/laravel projectname
OR
If you install some particular version, then you can use
composer create-project laravel/laravel project name "5.6"
If you did not mention any particular version, then it will install with the latest version.
A laravel service container is one of the most powerful tools that have been used to manage dependencies over the class and perform dependency injections.
Advantages of Service Container
- Freedom to manage class dependencies on object creation.
- Service contain as Registry.
- Ability to bind interfaces to concrete classes.
1. Retrieving Data from session
session()->get('key');
2. Retrieving All session data
session()->all();
3. Remove data from session
session()->forget('key'); or session()->flush();
4. Storing Data in session
session()->put('key', 'value');
In case you are using save()
$blog = new Blog;
$blog->title = ‘Best Interview Questions’;
$blog->save()
// Now you can use (after save() function we can use like this)
$blog->id // It will display last inserted id
In case you are using insertGetId()
$insertGetId = DB::table(‘blogs’)->insertGetId([‘title’ => ‘Best Interview Questions’]);
1. delete()
In case when we used to delete in Laravel then it removed records from the database table.
Example:
$delete = Post::where(‘id’, ‘=’, 1)->delete();
2. softDeletes()
To delete records permanently is not a good thing that’s why laravel used features are called SoftDelete. In this case, records did not remove from the table only delele_at value updated with current date and time.
Firstly we have to add a given code in our required model file.
use SoftDeletes;
protected $dates = ['deleted_at'];
After this, we can use both cases.
$softDelete = Post::where(‘id’, ‘=’, 1)->delete();
OR
$softDelete = Post::where(‘id’, ‘=’, 1)->softDeletes();
1. How to set Cookie
To set cookie value, we have to use Cookie::put('key', 'value');
2. How to get Cookie
To get cookie Value we have to use Cookie::get('key');
3. How to delete or remove Cookie
To remove cookie Value we have to use Cookie::forget('key')
4. How to check Cookie
To Check cookie is exists or not, we have to use Cache::has('key')
Laravel Auth is the process of identifying the user credentials with the database. Laravel managed it's with the help of sessions which take input parameters like username and password, for user identification. If the settings match then the user is said to be authenticated.
Auth is in-built functionality provided by Laravel; we have to configure.
We can add this functionality with php artisan make: auth
Auth is used to identifying the user credentials with the database.
with() function is used to eager load in Laravel. Unless of using 2 or more separate queries to fetch data from the database, we can use it with() method after the first command. It provides a better user experience as we do not have to wait for a longer period of time in fetching data from the database.
You can do this in various ways. Steps are given below:-
- Copy .htaccess file from public folder and now paste it into your root.
- Now rename server.php file/page to index.php on your root folder.
- Now you can remove /public word from URL and refresh the page. Now it will work.
Laravel supports various joins that's are given below:-
- Inner Join
DB::table('admin') ->join('contacts', 'admin.id', '=', 'contacts.user_id') ->join('orders', 'admin.id', '=', 'orders.user_id') ->select('users.id', 'contacts.phone', 'orders.price') ->get();
- Left Join / Right Join
$users = DB::table('admin') ->leftJoin('posts', 'admin.id', '=', 'posts.admin_id') ->get();
$users = DB::table('admin') ->rightJoin('posts', 'admin.id', '=', 'posts.admin_id') ->get(); - Cross Join
$user = DB::table('sizes') ->crossJoin('colours') ->get();
- Advanced Join
DB::table('admin') ->join('contacts', function ($join) { $join->on('admin.id', '=', 'contacts.admin_id')->orOn(...); }) ->get();
- Sub-Query Joins
$admin = DB::table('admin') ->joinSub($latestPosts, 'latest_posts', function ($join) { $join->on('admin.id', '=', 'latest_posts.admin_id'); })->get();
You can use request()->ip();
You can also use : Request::ip() but in this case, we have to call namespace like this: Use Illuminate\Http\Request;
We have to call Facades in our controller file with this :
use Illuminate\Support\Facades\Storage;
if($request->hasFile(file_name')) {
$file = Storage::putFile('YOUR FOLDER PATH', $request->file('file_name'));
}
Soft delete is a laravel feature that helps When models are soft deleted, they are not actually removed from our database. Instead, a deleted_at timestamp is set on the record. To enable soft deletes for a model, we have to specify the soft delete property on the model like this.
In model we have to use namespace use Illuminate\Database\Eloquent\SoftDeletes;
and we can use this
use SoftDeletes;
in our model property.
After that when we will use delete() query then records will not remove from our database. then a deleted_at timestamp is set on the record.
In Laravel, Facades are used to provide a static interface to classes available inside the application's service container.
Now, unlike conventional static method calls, facades can be mocked in Laravel. It can be done using the shouldRecieve method, which shall return an instance of a facade mock.
$value = Cache::get('key');
Cache::shouldReceive('get')->once()->with('key')->andReturn('value');
To use multiple databases in Laravel, follow these steps carefully.
- Ensure these settings in the .env file
- Add these following lines of code in the config/database.php file to clearly define the relationship between the two databases
- Execute the query with particular database.
1. Ensure these settings in the .env file
DB_CONNECTION=mysql
DB_HOST=localhost
DB_PORT=3306
DB_DATABASE=your_db_name
DB_USERNAME=bestinterviewquestion
[email protected]
DB_CONNECTION_SECOND=mysql
DB_HOST_SECOND=localhost
DB_PORT_SECOND=3306
DB_DATABASE_SECOND=your_db_name2
DB_USERNAME_SECOND=bestinterviewquestion
[email protected]
2. Add these following lines of code in the config/database.php file to clearly define the relationship between the two databases
'mysql' => [
'driver' => env('DB_CONNECTION'),
'host' => env('DB_HOST'),
'port' => env('DB_PORT'),
'database' => env('DB_DATABASE'),
'username' => env('DB_USERNAME'),
'password' => env('DB_PASSWORD'),
],
'mysql2' => [
'driver' => env('DB_CONNECTION_SECOND'),
'host' => env('DB_HOST_SECOND'),
'port' => env('DB_PORT_SECOND'),
'database' => env('DB_DATABASE_SECOND'),
'username' => env('DB_USERNAME_SECOND'),
'password' => env('DB_PASSWORD_SECOND'),
],
3. Execute Query
$users = DB::connection('your_db_name2')->select();
Laravel involves Eloquent ORM (Object Relational Mapper), which makes it fun to interact with the database. While using Eloquent, every database table contains their corresponding “Model” that is being used for interaction with that table. The eloquent model also allows the people to insert, update, and delete the records from the table. We can create Eloquent models using the make:model
command.
It has many types of relationships.
- One To One relationships
- One To Many relationships
- Many To Many relationships
- Has Many Through relationships
- Polymorphic relationships
- Many To Many Polymorphic relationships
After running the composer install in the project directory, the composer will generate the composer.lock file.It will keep a record of all the dependencies and sub-dependencies which is being installed by the composer.json.
We have to use the following artisan commands to enable/disable maintenance mode in Laravel 5.
Enable maintenance mode
php artisan down
Disable maintenance mode
php artisan up
In Laravel, dependency injection is a term used for the activity of injecting components into the user application. It’s a key element of agile architecture. The Laravel service container is a powerful tool that manages all class dependencies and performs dependency injection.
public function __construct(UserRepository $data)
{
$this->userdata = $data;
}
In this given an example, the UserController needs to retrieve users data from a data source(database). So, we can inject a service that is able to recover all users. In this example, our UserRepository most likely uses Eloquent to get user’s data from the database.
Laravel uses "Blade Template Engine". It is a straightforward and powerful templating engine that is provided with Laravel.
We can create all web pages of our sites to tell Google and other search engines like Bing, Yahoo etc about the organization of our site content. These search engine web crawlers read this file to more intelligently crawl our sites.
Here are the steps that helps you to create real time sitemap.xml file and these steps also helps to create dynamic XML files.
- Firstly we have to create a route for this in your
routes/web.php
file
Example
Route::get('sitemap.xml', '[email protected]')->name('sitemapxml');
- Now you can create SitemapController.php with artisan command
php artisan make:controller SitemapController
- Now you can put this code in your controller
public function index() {
$page = Page::where('status', '=', 1)->get();
return response()->view('sitemap_xml', ['page' => $page])->header('Content-Type', 'text/xml');
} - Now please create a view file in
resources/view/sitemap_xml.blade.php
file with this code - Put this code in that created view file
<?php echo '<?xml version="1.0" encoding="UTF-8"?>'; ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
@foreach ($page as $post)
<url>
<loc>{{ url($post->page_slug) }}</loc>
<lastmod>{{ $post->updated_at->tz('UTC')->toAtomString() }}</lastmod>
<priority>0.9</priority>
</url>
@endforeach
</urlset>
Laravel provides a variety of aggregate functions such as max, min, count,avg, and sum. We can call any of these functions after constructing our query.
$users = DB::table(‘admin’)->count();
$maxComment = DB::table(‘blogs’)->max('comments');
We can use skip() and take() both methods to limit the number of results in the query. skip() is used to skip the number of results and take() is used to get the number of result from the query.
$posts = DB::table('blog')->skip(5)->take(10)->get();
// skip first 5 records
// get 10 records after 5
It allows using objects without having to know how these objects are persisted. It is an abstraction of the data layer. It means that our business logic no need to know how data is retrieved. The business logic relies on the repository to get the correct data.
Basically it is used to decouple the data access layers and business logic in our application.
Vapor in Laravel is a serverless deployment platform auto-scaling and powered by AWS Lambda. It used to manage Laravel Infrastructure with the scalability and simplicity of serverless.
Yes, Laravel supports caching of popular backends such as Memcached and Redis.
If you want to rollback a specific migration, look in your migrations table, you’ll see each migration table has its own batch number. So, when you roll back, each migration that was part of the last batch gets rolled back.
Use this command to rollback the last batch of migration
php artisan migrate:rollback --step=1
Now, suppose you only want to roll back the very last migration, just increment the batch number by one. Then next time you run the rollback command, it’ll only roll back that one migration as it is a batch of its own.
To run test cases in Laravel, you should use the PHPUnit or artisan test command.
namespace Tests\Unit;
use PHPUnit\Framework\TestCase;
class ExampleTest extends TestCase
{
* @return void
public function testBasicTest()
{
$this->assertTrue(true);
}
}
The Eloquent cursor () method allows a user to iterate through the database records using a cursor, which will execute only a single query. This method is quite useful when processing large amounts of data to significantly reduce memory usage.
In laravel, we can call multiple Middlewares in Controller file and route file.
1. In Controller file, you can call like this.
public function __construct() {
$this->middleware(['revalidateBackHistory', 'validateUser']);
}
2. In route file, you can call multiple middleware like this.
Route::get('/', function () {
//
})->middleware(['firstMiddle', 'secondMiddle']);
Views contain the HTML provided by our application and separate our controller or application logic from our presentation logic. These are stored in the resources/views directory.
<html>
<body>
<h1>Best Interview Question<h1>
</body>
</html>
Faker is a type of module or packages which are used to create fake data for testing purposes. It can be used to produce all sorts of data.
It is used to generate the given data types.
- Lorem text
- Numbers
- Person i.e. titles, names, gender, etc.
- Addresses
- DateTime
- Phone numbers
- Internet i.e. domains, URLs, emails etc.
- Payments
- Colour, Files, Images
- UUID, Barcodes, etc
In Laravel, Faker is used basically for testing purposes.
- In Laravel, Queues are very useful for taking jobs, pieces of asynchronous work, and sending them to be performed by other processes and this is useful when making time-consuming API calls that we don’t want to make your users wait for before being served their next page.
- Another advantage of using queues is that you don’t want to work the lines on the same server as your application. If your jobs involve intensive computations, then you don’t want to take risk those jobs taking down or slowing your web server.
Please run below artisan commands step wise step.
php artisan config:clear
php artisan cache:clear
composer dump-autoload
php artisan view:clear
php artisan route:clear
Laravel offers a tool to include dummy data to the database automatically. This process is called seeding. Developers can add simply testing data to their database table using the database seeder. It is extremely useful as testing with various data types allows developers to detect bugs and optimize performance. We have to run the artisan command make:seeder
to generate a seeder, which will be placed in the directory database/seeds
as like all others.
How to create database seeder
To generate a seeder, run the make:seeder
Artisan command. All seeders generated by the laravel will be placed in the database/seeds
directory:
php artisan make:seeder AdminTableSeeder
With the help of update() function, we can update our data in the database according to the condition.
Blog::where(['id' => $id])->update([
'title' => ’Best Interview Questions’,
‘content’ => ’Best Interview Questions’
]);
OR
DB::table("blogs")->where(['id' => $id])->update([
'title' => ’Best Interview Questions’,
‘content’ => ’Best Interview Questions’
]);
Blog::where(['id' => 5])->orWhere([‘username’ => ‘[email protected]’])->update([
'title' => ‘Best Interview Questions’,
]);
Laravel provides various methods that we can use in queries to get records with our conditions.
These methods are given below
- where()
- orWhere()
- whereBetween()
- orWhereBetween()
- whereNotBetween()
- orWhereNotBetween()
- wherein()
- whereNotIn()
- orWhereIn()
- orWhereNotIn()
- whereNull()
- whereNotNull()
- orWhereNull()
- orWhereNotNull()
- whereDate()
- whereMonth()
- whereDay()
- whereYear()
- whereTime()
- whereColumn()
- orWhereColumn()
- whereExists()
updateOrInsert() method is used to update an existing record in the database if matching the condition or create if no matching record exists.
Its return type is Boolean.
Syntax
DB::table(‘blogs’)->updateOrInsert([Conditions],[fields with value]);
DB::table(‘blogs’)->updateOrInsert(
['email' => '[email protected]', 'title' => 'Best Interview Questions'],
['content' => 'Test Content']
);
We can use hasTable() to check table exists in our database or not.
Syntax
Schema::hasTable('users');
// here users are the table name.
if(Schema::hasTable('users')) {
// table is exists
} else {
// table is not exist
}
if(Schema::hasColumn('admin', 'username')) ; //check whether admin table has username column
{
// write your logic here
}
Inserts(): This method is used for insert records into the database table. No need the “id” should be autoincremented or not in the table.
Example
DB::table('bestinterviewquestion_users')->insert(
['title' => 'Best Interview Questions', 'email' => ‘[email protected]’]
);
It will return true or false.
insertGetId(): This method is also used for insert records into the database table. This method is used in the case when an id field of the table is auto incrementing.
It returns the id of current inserted records.
Example
$id = DB::table('bestinterviewquestion_users')->insert(
['title' => 'Best Interview Questions', 'email' => ‘[email protected]’]
);
Laravel accessors and mutators are customs, user-defined methods that allow you to format Eloquent attributes. Accessors are used to format attributes when you retrieve them from the database.
1. Defining an accessor
The syntax of an accessor is where getNameAttribute()
Name is capitalized attribute you want to access.
public function getNameAttribute($value)
{
return ucfirst($value);
}
2. Defining a mutator
Mutators format the attributes before saving them to the database.
The syntax of a mutator function is where setNameAttribute()
Name is a camel-cased column you want to access. So, once again, let’s use our Name column, but this time we want to make a change before saving it to the database:
public function setNameAttribute($value)
{
$this->attributes['name'] = ucfirst($value);
}
Please update 'default' => env('DB_CONNECTION', 'mysql'),
in config/database.php
. Update MySQL as a database whatever you want.
Lumen is a newly introduced micro PHP framework which is a faster, smaller and leaner version of a full web application framework. It is introduced by Taylor Otwell, the creator of Laravel. It uses the same components as Laravel, but especially for microservices.
It has a simple installer like Laravel. You have to use this command to install lumen.
composer global require "laravel/lumen-installer=~1.0"
You can use an artisan command php artisan --version
to know the laravel version.
You can use php artisan key:generate
to generate your application key.
Here is an example to understand the concept of using group_concat() to join in Laravel. We have 3 tables like "dynamic_forms", "dynamic_forms_mapping", "categories".
$list = DB::table('dynamic_forms')
->select("dynamic_forms.*" ,DB::raw("(GROUP_CONCAT(wf_categories.name SEPARATOR ', ')) as category"))
->leftjoin("dynamic_forms_mapping", "dynamic_forms_mapping.form_id","=","dynamic_forms.id")
->leftjoin("categories", "dynamic_forms_mapping.category_id","=","categories.id")
->groupBy('dynamic_forms.id')
->where('dynamic_forms.status', 1)
->get();
You can extend the login expire time with config\session.php this file location. Just update lifetime the value of the variable. By default it is 'lifetime' => 120. According to your requirement update this variable.
'lifetime' => 180
Artisan is a type of the "command line interface" using in Laravel. It provides lots of helpful commands for you while developing your application. We can run these command according to our need.
Laravel supports various artisan commands like
- php artisan list;
- php artisan –version
- php artisan down;
- php artisan help;
- php artisan up;
- php artisan make:controller;
- php artisan make:mail;
- php artisan make:model;
- php artisan make:migration;
- php artisan make:middleware;
- php artisan make:auth;
- php artisan make:provider etc.;
Laravel Gate holds a sophisticated mechanism that ensures the users that they are authorized for performing actions on the resources. The implementation of the models is not defined by Gate. This renders the users the freedom of writing each and every complex spec of the use case that a user has in any way he/she wishes. Moreover, the ACL packages can be used as well with the Laravel Gate. With the help of Gate, users are able to decouple access logic and business logic. This way clutter can be removed from the controllers.
Developers use packages to add functionality to Laravel. Packages can be almost anything, from great workability with dates like Carbon or an entire BDD testing framework such as Behat. There are standalone packages that work with any PHP frameworks, and other specially interned packages which can be only used with Laravel. Packages can include controllers, views, configuration, and routes that can optimally enhance a Laravel application.
There are many packages are available nowadays also laravel has some official packages that are given below:-
- Cashier
- Dusk
- Envoy
- Passport
- Socialite
- Scout
- Telescope etc
Validation is the most important thing while designing an application. It validates the incoming data. It uses ValidatesRequests trait which provides a convenient method to authenticate incoming HTTP requests with powerful validation rules.
Here are some Available Validation Rules in Laravel are listed:-
- Alpha
- Image
- Date Format
- IP Address
- URL
- Numeric
- Size
- Min , Max
- Unique with database etc
Laravel is an appropriate choice for PHP builders to use for building an API, especially when a project’s necessities are not exactly defined. It's a comprehensive framework suitable for any type of application development, is logically structured, and enjoys robust community support.
Laravel includes factors for not solely API development, but front-end templating and singe-page software work, and other aspects that are totally unrelated to only building a net utility that responds to REST Http calls with JSON.
With this @extends('layouts.master')
we can extend this master layout in any view file.
In this example layouts are a folder that is placed in resources/views
available and the master file will be there. Now "master.blade.php" is a layout file.
We can use
return redirect('/')->withErrors('You can type your message here');
return redirect('/')->with('variableName', 'You can type your message here');
return redirect('/')->route('PutRouteNameHere');
<script type="text/javascript">
$(document).ready(function() {
$("FORMIDORCLASS").submit(function(e){
// FORMIDORCLASS will your your form CLASS ot ID
e.preventDefault();
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN': $('meta[name="_token"]').attr('content')
// you have to pass in between tag
}
})
var formData = $("FORMIDORCLASS").serialize();
$.ajax({
type: "POST",
url: "",
data : formData,
success: function( response ) {
// Write here your sucees message
}, error: function(response) {
// Write here your error message
},
});
return false;
});
});
</script>
php artisan make:model ModelNameEnter -mcr
$valiable1 = 'Best';
$valiable2 = 'Interview';
$valiable3 = 'Question';
return view('frontend.index', compact('valiable1', valiable2', valiable3'));
In you View File use can display by {{ $valiable1 }}
or {{ $valiable2 }}
or {{ $valiable3 }}
We have to pass protected $table = 'YOUR TABLE NAME'; in your respective Model
namespace App;
use Illuminate\Database\Eloquent\Model;
class Login extends Model
{
protected $table = 'admin';
static function logout() {
if(session()->flush() || session()->regenerate()) {
return true;
}
}
}
- Run this php artisan make:rule OlympicYear
- After that command it generates a file app/Rules/OlympicYear.php
- We can write rule in the passes() in OlympicYear.php generated file. It will return true or false depending on condition, which is this in our case
public function passes($attribute, $value)
{
return $value >= 1896 && $value <= date('Y') && $value % 4 == 0;
} - Next, we can update error message to be this:
public function message()
{
return ':attribute should be a year of Olympic Games';
} - Finally, we use this class in controller's store() method we have this code:
public function store(Request $request)
{
$this->validate($request, ['year' => new OlympicYear]);
}
Where Null Query
DB::table('users')->whereNull('name')->get();
Where Not Null Query
DB::table('users')->whereNotNull('name')->get();
ACL Stands for Access Control List.
If you needed to control get entry to certain sections of the site, or flip on or off unique portions of a web page for non-admins, or ensure any person can only edit their very own contacts, you wanted to deliver in a device like BeatSwitch Lock or hand-roll the functionality, which would be something referred to as ACL: Access Control Lists or basically the capability to outline a persons' capability to do and see certain matters primarily based on attributes of their person record.
Queues in Laravel are used by developers to create smooth application cycle by stacking complex tasks as jobs and dispatching these heavy jobs only with user permission or when it doesn’t disrupt the user experience.
We can add multiple AND operator at in a single where() conditions as well as we can also add separate where() for particular AND condition.
DB::table('client')->where('status', '=', 1)->where('name', '=', 'bestinterviewquestion.com')->get();
DB::table('client')->where(['status' => 1, 'name' => 'bestinterviewquestion.com'])->get();
Blade is very simple and powerful templating engine that is provided with Laravel. Laravel uses "Blade Template Engine".
The Laravel 5.1 framework comprises functionality named broadcasting events. This new functionality makes it quite easy to build real-time applications in PHP. And with this, an app will be able to publish the events to a number of real-time cloud-based PubSub solutions, such as Pusher, or Redis. Also, with this functionality called the broadcasting events which is built into the Laravel 5.1, it now became easier creating real-time applications for the PHP developers. This latest real-time capability unbars numerous possibilities that were available only to applications written for the other platforms such as Node.js.
Mix in Laravel renders one fluent API to define Webpack creation steps for the application of Laravel that uses various common CSS as well as JavaScript preprocessors. With the help of one easy method of chaining, the user is able to fluently define the asset pipeline.
mix.js('resources/js/app.js', 'public/js') // You can also use your custom folder here
.sass('resources/sass/app.scss', 'public/css');
It is an array which contains all those fields of table which can be create directly new record in your Database table.
class User extends Model {
protected $fillable = ['username', 'password', 'phone'];
}
It is the reverse of fillable. When a guarded specifies which fields are not mass assignable.
class User extends Model {
protected $guarded = ['user_type'];
}
use Illuminate\Support\Facades\Auth;
$userinfo = Auth::user();
print_r($userinfo );
You can use the following syntax to check ajax request in laravel.
if ($request->ajax()) {
// Now you can write your code here.
}
To check the email value is sent or not in request, you can use $request->has('email')
if($request->has('email')) {
// email value is sent from request
} else {
// email value not sent from request
}
Laravel includes a number of global "helper" string and array functions. These are given below:-
Laravel Array Helper functions
- Arr::add()
- Arr::has()
- Arr::last()
- Arr::only()
- Arr::pluck()
- Arr::prepend() etc
Laravel String Helper functions
- Str::after()
- Str::before()
- Str::camel()
- Str::contains()
- Str::endsWith()
- Str::containsAll() etc
You can cut out a route from CSRF verification by using adding the route to $except property at VerifyCsrfToken middleware.
protected $except = [
'admin/*/edit/*'
];
Conclusion
This is highly recommended you go through all these laravel interview questions twice or thrice before going to an interview. Also, try to give an example of every question wherever possible. This will add a bonus point to your plate and shows your expertise in laravel coding. Also, make sure your answers should not be lengthy or sounds like a boring story. Keep your answers short and clear with the help of examples.