PHP ORM with Eloquent - Object-Relational Mapping


Object-Relational Mapping (ORM) is a programming technique that allows you to interact with your database using object-oriented programming instead of writing raw SQL queries. Eloquent is the ORM used in the Laravel framework. In this guide, we'll explore PHP ORM with Eloquent:


What is Eloquent?

Eloquent is Laravel's implementation of the Active Record pattern, a type of ORM. It allows you to interact with your database tables using PHP classes and methods instead of writing SQL queries directly. Eloquent models represent database tables, and each model instance corresponds to a row in the table.


Setting Up Eloquent

To use Eloquent, you need to set up Laravel or install it as a standalone component. Once installed, configure your database connection in Laravel's configuration files. Laravel supports various database systems such as MySQL, PostgreSQL, SQLite, and more.


Defining Models

In Eloquent, you define models to represent database tables. Each model corresponds to a table and defines the table's schema and relationships. Models are usually stored in the "app/Models" directory.

// Example User model
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
    protected $table = 'users';
    protected $primaryKey = 'id';
}
?>

CRUD Operations

Eloquent provides simple methods for performing CRUD (Create, Read, Update, Delete) operations. You can use methods like 

create()
, 
find()
, 
update()
, and 
delete()
to interact with your database records.


Query Building

You can build complex queries using Eloquent's query builder. This allows you to create advanced database queries with PHP code. For example:

$users = User::where('age', '>', 18)
    ->orderBy('name', 'asc')
    ->get();

Relationships

Eloquent supports defining and working with relationships between models. You can define relationships like one-to-one, one-to-many, many-to-many, etc. This simplifies working with related data in your application.


Migrations

Eloquent provides a mechanism called "migrations" for creating and modifying database tables. Migrations allow you to version-control your database schema and collaborate with others more effectively.

// Creating a users table migration
php artisan make:migration create_users_table

Validation

Eloquent includes built-in validation for your models. You can define validation rules within your model to ensure that only valid data is stored in the database.

// Example validation rules in a model
protected $rules = [
    'name' => 'required|string|max:255',
    'email' => 'required|email|unique:users',
];

Conclusion

Eloquent simplifies database interactions in PHP applications by providing a powerful and user-friendly ORM. It enables you to work with databases using PHP objects and methods, making your code cleaner, more maintainable, and efficient. Eloquent is a vital tool in Laravel development for managing database-related tasks.