Laravel 8 Database & Eloquent ORM Explained 📦🔍

Laravel provides a powerful database system using Eloquent ORM (Object-Relational Mapping), making it easy to interact with databases.

1. Database Configuration

Laravel uses .env file for database settings.

✅ Open .env and update:

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

💡 Run Migration to check if the connection works:

php artisan migrate

2. Creating a Model & Migration

Eloquent uses Models to interact with database tables.

✅ Run this command to create a model with a migration file:

php artisan make:model Product -m

This creates:

• Model: app/Models/Product.php
• Migration: database/migrations/xxxx_xx_xx_create_products_table.php

📄 File: database/migrations/xxxx_xx_xx_create_products_table.php Modify the up() method:

public function up()
{
    Schema::create('products', function (Blueprint $table) {
        $table->id();
        $table->string('name');
        $table->decimal('price', 8, 2);
        $table->text('description')->nullable();
        $table->timestamps();
    });
}

💡 Run Migration to create the table:

php artisan migrate

3. Eloquent Model Setup

📄 File: app/Models/Product.php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    use HasFactory;

    protected $fillable = ['name', 'price', 'description']; // Mass assignable fields
}

4. Performing CRUD Operations

Eloquent makes it easy to perform Create, Read, Update, Delete (CRUD) operations.

a) Insert Data (Create)

✅ Using Eloquent

use App\Models\Product;

Product::create([
    'name' => 'Laptop',
    'price' => 49999.99,
    'description' => 'A high-performance laptop'
]);

✅ Using save() Method

$product = new Product();
$product->name = "Smartphone";
$product->price = 19999.99;
$product->description = "A powerful smartphone";
$product->save();

b) Fetch Data (Read)

✅ Get all records

$products = Product::all();

✅ Get a single record by ID

$product = Product::find(1);

✅ Find by a specific column

$product = Product::where('name', 'Laptop')->first();

✅ Looping through records

foreach (Product::all() as $product) {
    echo $product->name . " - ₹" . $product->price . "<br>";
}

c) Update Data

✅ Update using find()

$product = Product::find(1);
$product->price = 47999.99;
$product->save();

✅ Update using update()

Product::where('name', 'Laptop')->update(['price' => 45999.99]);

d) Delete Data

✅ Delete a record

$product = Product::find(1);
$product->delete();

✅ Delete using where()

Product::where('name', 'Smartphone')->delete();

✅ Delete all records

Product::truncate();

5. Eloquent Relationships

Eloquent makes handling relationships easy.

a) One-to-One Relationship

A User has one Profile.

✅ Migration: users Table

Schema::create('users', function (Blueprint $table) {
    $table->id();
    $table->string('name');
    $table->timestamps();
});

✅ Migration: profiles Table

Schema::create('profiles', function (Blueprint $table) {
    $table->id();
    $table->unsignedBigInteger('user_id')->unique();
    $table->text('bio');
    $table->timestamps();

    $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
});

✅ Model: User.php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

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

✅ Model: Profile.php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

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

✅ Fetching User Profile

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

b) One-to-Many Relationship

A Category has many Products.

✅ Model: Category.php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    public function products()
    {
        return $this->hasMany(Product::class);
    }
}

✅ Fetching All Products in a Category

$category = Category::find(1);
foreach ($category->products as $product) {
    echo $product->name;
}

c) Many-to-Many Relationship

A User has many Roles, and a Role belongs to many Users.

✅ Pivot Table Migration

Schema::create('role_user', function (Blueprint $table) {
    $table->id();
    $table->unsignedBigInteger('user_id');
    $table->unsignedBigInteger('role_id');
    $table->timestamps();
});

✅ Model: User.php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function roles()
    {
        return $this->belongsToMany(Role::class);
    }
}

✅ Model: Role.php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Role extends Model
{
    public function users()
    {
        return $this->belongsToMany(User::class);
    }
}

✅ Assign Role to a User

$user = User::find(1);
$user->roles()->attach(2); // Assign role with ID 2

✅ Fetching Roles for a User

$user = User::find(1);
foreach ($user->roles as $role) {
    echo $role->name;
}

6. Query Builder vs. Eloquent

Laravel provides Query Builder as an alternative to Eloquent.

✅ Using Query Builder

use Illuminate\Support\Facades\DB;

$products = DB::table('products')->get();

✅ Using Eloquent

$products = Product::all();

🚀 Eloquent is recommended as it provides a more readable and maintainable approach.

7. Database Seeding

Seeding allows inserting dummy data.

✅ Create a Seeder

php artisan make:seeder ProductSeeder

📄 File: database/seeders/ProductSeeder.php

use Illuminate\Database\Seeder;
use App\Models\Product;

class ProductSeeder extends Seeder
{
    public function run()
    {
        Product::create([
            'name' => 'Tablet',
            'price' => 29999.99,
            'description' => 'A lightweight tablet'
        ]);
    }
}

✅ Run Seeder

php artisan db:seed --class=ProductSeeder

Conclusion

Eloquent ORM makes database handling simple, fast, and readable in Laravel. 🚀✨

Need any clarification? 😊