Introduction to Standalone Eloquent ORM

The Eloquent ORM from Laravel can be utilized independently of the full framework. This powerful database toolkit offers several advantages for PHP developers seeking a robust database abstraction layer without the entire Laravel ecosystem.

Benefits of Using Standalone Eloquent

• Expressive and intuitive syntax for database operations
• Powerful query builder with fluent interface
• ActiveRecord-style ORM for object-relational mapping
• Schema builder for database migrations
• Strong performance characteristics
• High code reusability across projects

System Requirements

The standalone version is compatible with PHP 7.2+ and supports the following database systems:

• MySQL 5.6+
• PostgreSQL 9.4+
• SQLite 3.8.8+
• SQL Server 2017+

Installation

Begin by installing the package via Composer:

composer require illuminate/database

For projects requiring Eloquent observers, you'll also need:

composer require "illuminate/events"

Configuration and Setup

The first step is to create a Capsule manager instance. Capsule provides a convenient way to configure the database components outside of Laravel:

<?php
use Illuminate\Database\Capsule\Manager as Capsule;
use Illuminate\Events\Dispatcher;
use Illuminate\Container\Container;

$capsule = new Capsule;

$capsule->addConnection([
    'driver'    => 'mysql',
    'host'      => 'localhost',
    'database'  => 'your_database',
    'username'  => 'your_username',
    'password'  => 'your_password',
    'charset'   => 'utf8',
    'collation' => 'utf8_unicode_ci',
    'prefix'    => '',
]);

// Optional: Set the event dispatcher for Eloquent models
$capsule->setEventDispatcher(new Dispatcher(new Container));

// Optional: Make Capsule available globally via static methods
$capsule->setAsGlobal();

// Optional: Boot the Eloquent ORM
$capsule->bootEloquent();
?>

Using the Query Builder

Once configured, you can use the query builder to interact with your database:

// Retrieve users with more than 100 votes
$activeUsers = Capsule::table('users')
    ->where('votes', '>', 100)
    ->get();

// Execute raw SQL with parameter binding
$results = Capsule::select('SELECT * FROM users WHERE id = ?', [1]);

Using the Schema Builder

The schema builder allows you to modify your dtaabase structure:

// Create a new table
Capsule::schema()->create('users', function ($table) {
    $table->increments('id');
    $table->string('email')->unique();
    $table->timestamps();
});

// Modify an existing table
Capsule::schema()->table('users', function ($table) {
    $table->string('first_name');
    $table->string('last_name');
});

Using Eloquent Models

Define your models to work with Eloquent ORM:

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

class User extends Model
{
    // Specify the table if not following naming conventions
    protected $table = 'users';
    
    // Define which fields are mass assignable
    protected $fillable = ['name', 'email', 'password'];
    
    // Define any relationships with other models
    public function posts()
    {
        return $this->hasMany('Post');
    }
}
?>

Once your models are defined, you can interact with your database:

// Retrieve all users
$allUsers = User::all();

// Find a user by ID
$user = User::find(1);

// Query users with conditions
$activeUsers = User::where('active', 1)->get();

// Create a new user
$newUser = User::create([
    'name' => 'John Doe',
    'email' => 'john@example.com',
    'password' => bcrypt('password')
]);

// Update a user
$user = User::find(1);
$user->name = 'Jane Doe';
$user->save();

Practical Implementation Example

Here's a complete example of how to implement the standalone Eloquent ORM in a project:

<?php
// Include Composer autoloader
require __DIR__ . '/vendor/autoload.php';

// Define your Eloquent model
class User extends Illuminate\Database\Eloquent\Model {}

// Database configuration
$dbConfig = [
    'driver' => 'mysql',
    'host' => 'localhost',
    'database' => 'your_database',
    'username' => 'your_username',
    'password' => 'your_password',
    'charset' => 'utf8',
    'collation' => 'utf8_unicode_ci',
    'prefix' => '',
];

// Initialize Capsule
$capsule = new Illuminate\Database\Capsule\Manager as Capsule;
$capsule->addConnection($dbConfig);
$capsule->setAsGlobal();
$capsule->bootEloquent();

// Example usage
$users = User::orderBy('created_at', 'desc')->limit(10)->get();
foreach ($users as $user) {
    echo $user->name . ': ' . $user->email . PHP_EOL;
}
?>

Remember to implement proper autoloading for your models in a production environment to ensure all classes are properly loaded.