Chapter 2.2: Creating the Planet Model

Time to learn: 45 minutes

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1. The Model in Laravel: A Blueprint for a Celestial Object

In the MVC (Model-View-Controller) architecture, the model is:

• 📦 A container for data (planet parameters)
• 🔌 An interface for working with the database
• 🛡️ The center of the application's business logic

💡 Space Analogy: The Planet model = A planet's blueprint in the Mission Control Center's computer. With it, you can:

• Create a new planet in the catalog (INSERT)
• Get data about Mars (SELECT)
• Update information about the atmosphere (UPDATE)

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2. Creating a Model and Migration

Laravel uses the Artisan CLI—your project's "control panel."

Step 1: Generating the model with a migration

php artisan make:model Planet -m

What was created:

app/
  └── Models/
      └── Planet.php    ← Model
database/
  └── migrations/
      └── 2025_08_04_000000_create_planets_table.php  ← Migration

Artisan Flags:

• -m → Create a migration
• -c → Create a controller
• -r → Resource controller

💡 Pro Tip: These flags can be combined for maximum efficiency. The command php artisan make:model Planet -mcr will create a model, a migration, and a resource controller to manage that model all at once. This saves a lot of time.

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3. Configuring the Planet Model

Open app/Models/Planet.php:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Planet extends Model
{
    // Table name (default: 'planets')
    // Laravel automatically assumes the table name is the plural, snake_case version of the model name (Planet -> planets).
    // Therefore, this property isn't strictly necessary here, but it's useful for clarity.
    protected $table = 'planets';

    // The attributes that are mass assignable.
    protected $fillable = [
        'name',
        'description',
        'size_km',
        'solar_system',
        'image_url'
    ];

    // The attributes that should be cast.
    protected $casts = [
        'size_km' => 'integer'
    ];
}

Property Explanation:

Property	Meaning	Example Data
$table	Table name in the DB	planets
$fillable	Fields for mass assignment	name, size_km
$casts	Automatic type casting	size_km: integer

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4. Designing the Planets Table

Before editing the migration, let's define the "planet" structure:

Field	Data Type	Description	Example Value
id	BIGINT (PK)	Unique ID	1
name	VARCHAR(255)	Planet's name	"Mars"
description	TEXT	Description	"The Red Planet..."
size_km	INTEGER	Diameter in km	6779
solar_system	VARCHAR(100)	Solar system	"Solar System"
image_url	VARCHAR(2048)	Photo URL (can be null)	"https://..."
created_at	TIMESTAMP	Creation date	2025-08-04 12:00:00
updated_at	TIMESTAMP	Update date	2025-08-05 09:30:00

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5. Editing the Migration

Open the migration file in database/migrations/..._create_planets_table.php:

<?php
use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreatePlanetsTable extends Migration
{
    public function up()
    {
        Schema::create('planets', function (Blueprint $table) {
            $table->id(); // BIGINT auto-increment

            $table->string('name')->unique();
            $table->text('description');
            $table->integer('size_km');
            $table->string('solar_system', 100);
            $table->string('image_url', 2048)->nullable();

            $table->timestamps(); // created_at + updated_at
        });
    }

    public function down()
    {
        Schema::dropIfExists('planets');
    }
}

Key Points:

• ->unique() → Ensures names are unique
• ->nullable() → The field can be empty
• timestamps() → Automatic date management

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6. Running the Migration (Preview)

Although we'll run this in Chapter 2.3, let's see what it looks like:

php artisan migrate

Expected Output:

Migrating: 2025_08_04_000000_create_planets_table
Migrated:  2025_08_04_000000_create_planets_table (32.15ms)

Checking in pgAdmin 4:

1. Open the space_api database → Schemas → Tables
2. The planets table should appear with your fields

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7. Alternative Approach: Code Generators

To speed up development, you can use packages:

• Laravel Blueprint - creates models/migrations from a YAML definition
• InfyOm Laravel Generator - a generator based on a DB schema

Blueprint Example:

models:
  Planet:
    name: string:255
    description: text
    size_km: integer
    solar_system: string:100
    image_url: string:2048? # The '?' character means the field is nullable

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Review Quiz

1. The Artisan command to create a model and its associated migration is:

a) php artisan make:model Planet -m b) php artisan create:model Planet c) php artisan model:new Planet --m

2. The `$fillable` property in a model is used for:

a) Protection against mass assignment b) Automatic data encryption c) Describing foreign keys

3. `nullable()` in a migration means:

a) The field is required b) The field can be empty c) The field will be deleted

4. The field type for a long planet description is:

a) string b) text c) varchar

5. The `timestamps()` method creates:

a) Only created_at b) created_at and updated_at c) id, created_at, updated_at

Check

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🚀 Chapter Summary: You've created a "digital twin" of a planet! Your project now has:

• 🪐 A Planet model with business logic
• 📊 A migration for the planets table in PostgreSQL
• 🛠️ Configured model properties (fillable, casts)

Get the database ready! In the next chapter, we will run the migration and populate the universe with its first planets.

📌 Checkpoint:

Make sure the Planet.php and ..._create_planets_table.php files are created in the correct directories.

⚠️ If Artisan gives an error:

• Check that you are in the project folder
• Make sure dependencies are installed (composer install)
• For Windows: add PHP and Composer to your PATH