Laravel Database & Eloquent ORM (Beginner Friendly)

📌 What is Eloquent ORM?

Eloquent is Laravel’s built-in Object-Relational Mapping (ORM) system.
It allows you to interact with databases using PHP objects, rather than writing raw SQL queries.

Benefits:

• Clean, readable code
• Simplifies CRUD operations
• Supports relationships (one-to-one, one-to-many, many-to-many)
• Built-in query builder

⚙️ Database Setup in Laravel

1. Configure .env file

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel_db
DB_USERNAME=root
DB_PASSWORD=

2. Run Migration

Laravel comes with a users table by default. Run:

php artisan migrate

• Creates tables defined in database/migrations/
• Each migration represents a table

🔹 Creating a Model

Use Artisan command:

php artisan make:model Post

• Creates app/Models/Post.php
• Represents posts table (Laravel uses plural table name by default)

Basic CRUD with Eloquent

Create Record

$post = new Post;
$post->title = "Laravel ORM Tutorial";
$post->body = "Learn Eloquent ORM in Laravel step by step.";
$post->save();

Read Record

$posts = Post::all(); // Fetch all posts
$post = Post::find(1); // Fetch post by ID

Update Record

$post = Post::find(1);
$post->title = "Updated Title";
$post->save();

Delete Record

$post = Post::find(1);
$post->delete();

🔹 Eloquent Relationships

Eloquent makes database relationships easy.

1. One-to-One

User has one Profile

User.php:

public function profile() {
    return $this->hasOne(Profile::class);
}

Profile.php:

public function user() {
    return $this->belongsTo(User::class);
}

Access:

$user = User::find(1);
$profile = $user->profile;

2. One-to-Many

Category has many Posts

Category.php:

public function posts() {
    return $this->hasMany(Post::class);
}

Post.php:

public function category() {
    return $this->belongsTo(Category::class);
}

Access:

$category = Category::find(1);
$posts = $category->posts;

3. Many-to-Many

Posts belong to many Tags

Post.php:

public function tags() {
    return $this->belongsToMany(Tag::class);
}

Tag.php:

public function posts() {
    return $this->belongsToMany(Post::class);
}

• Pivot table required: post_tag
• Access:

$post = Post::find(1);
$tags = $post->tags;

🔹 Query Builder Examples

Eloquent provides a fluent query builder:

$posts = Post::where('status', 'published')
             ->orderBy('created_at', 'desc')
             ->take(5)
             ->get();

Other useful methods:

• first()
• pluck('title')
• count()
• exists()

🔹 Using Migrations

Migrations allow you to version control your database.

Example: Create posts table

php artisan make:migration create_posts_table

database/migrations/xxxx_create_posts_table.php:

public function up() {
    Schema::create('posts', function (Blueprint $table) {
        $table->id();
        $table->string('title');
        $table->text('body');
        $table->timestamps();
    });
}

Run migration:

php artisan migrate

📌 Key Takeaways

This week you learned:

• How to configure database in Laravel
• How to use Eloquent ORM for CRUD operations
• How to define one-to-one, one-to-many, and many-to-many relationships
• How to use query builder for filtering and sorting
• How to use migrations to manage database schema