**Course Title:** Mastering Laravel Framework: Building Scalable Modern Web Applications **Section Title:** Working with Databases and Eloquent ORM **Topic:** Create database migrations, models, and relationships to build a database-driven blog system.(Lab topic) In this lab topic, we'll put our knowledge of Laravel's database migrations and Eloquent ORM into practice by building a database-driven blog system. We'll create the necessary migrations, models, and relationships to store and manage blog posts, authors, and categories. **Step 1: Plan the Database Schema** Before we start creating migrations and models, let's define the database schema for our blog system. We'll need the following tables: * `posts` * `categories` * `authors` * `post_categories` (many-to-many pivot table) The `posts` table will have the following columns: * `id` (primary key) * `title` * `content` * `author_id` (foreign key referencing the `id` column in the `authors` table) * `created_at` * `updated_at` The `categories` table will have the following columns: * `id` (primary key) * `name` * `created_at` * `updated_at` The `authors` table will have the following columns: * `id` (primary key) * `name` * `email` * `created_at` * `updated_at` The `post_categories` table will have the following columns: * `id` (primary key) * `post_id` (foreign key referencing the `id` column in the `posts` table) * `category_id` (foreign key referencing the `id` column in the `categories` table) * `created_at` * `updated_at` **Step 2: Create Database Migrations** Now that we have our database schema planned, let's create the necessary database migrations using Laravel's migration tool. ```bash php artisan make:migration create_posts_table php artisan make:migration create_categories_table php artisan make:migration create_authors_table php artisan make:migration create_post_categories_table ``` Next, let's define the schema for each table in the corresponding migration file: `create_posts_table.php`: ```php use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; class CreatePostsTable extends Migration { /** * Run the migrations. * * @return void */ public function up() { Schema::create('posts', function (Blueprint $table) { $table->id(); $table->string('title'); $table->text('content'); $table->foreignId('author_id')->constrained(); $table->timestamps(); }); } /** * Reverse the migrations. * * @return void */ public function down() { Schema::dropIfExists('posts'); } } ``` `create_categories_table.php`: ```php use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; class CreateCategoriesTable extends Migration { /** * Run the migrations. * * @return void */ public function up() { Schema::create('categories', function (Blueprint $table) { $table->id(); $table->string('name'); $table->timestamps(); }); } /** * Reverse the migrations. * * @return void */ public function down() { Schema::dropIfExists('categories'); } } ``` `create_authors_table.php`: ```php use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; class CreateAuthorsTable extends Migration { /** * Run the migrations. * * @return void */ public function up() { Schema::create('authors', function (Blueprint $table) { $table->id(); $table->string('name'); $table->string('email'); $table->timestamps(); }); } /** * Reverse the migrations. * * @return void */ public function down() { Schema::dropIfExists('authors'); } } ``` `create_post_categories_table.php`: ```php use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; class CreatePostCategoriesTable extends Migration { /** * Run the migrations. * * @return void */ public function up() { Schema::create('post_categories', function (Blueprint $table) { $table->id(); $table->foreignId('post_id')->constrained(); $table->foreignId('category_id')->constrained(); $table->timestamps(); }); } /** * Reverse the migrations. * * @return void */ public function down() { Schema::dropIfExists('post_categories'); } } ``` Next, let's migrate our database schema: ```bash php artisan migrate ``` **Step 3: Create Eloquent Models** Now that we have our database schema in place, let's create the corresponding Eloquent models for each table. `Post.php`: ```php namespace App\Models; use Illuminate\Database\Eloquent\Model; class Post extends Model { protected $fillable = [ 'title', 'content', 'author_id', ]; public function author() { return $this->belongsTo(Author::class); } public function categories() { return $this->belongsToMany(Category::class); } } ``` `Category.php`: ```php namespace App\Models; use Illuminate\Database\Eloquent\Model; class Category extends Model { protected $fillable = [ 'name', ]; public function posts() { return $this->belongsToMany(Post::class); } } ``` `Author.php`: ```php namespace App\Models; use Illuminate\Database\Eloquent\Model; class Author extends Model { protected $fillable = [ 'name', 'email', ]; public function posts() { return $this->hasMany(Post::class); } } ``` **Step 4: Create Relationships** Now that we have our models and database schema in place, let's define the relationships between them. We've already defined the relationships between the `Post`, `Author`, and `Category` models. Here's a quick summary: * A `Post` belongs to one `Author`. * A `Post` belongs to many `Category` instances. * A `Category` belongs to many `Post` instances. * An `Author` has many `Post` instances. **Conclusion** In this lab topic, we've created the necessary database migrations, Eloquent models, and relationships to build a database-driven blog system using Laravel's Eloquent ORM. We've defined the relationships between the `Post`, `Author`, and `Category` models, and we're now ready to start building our blog system. **What's Next?** In our next topic, we'll learn about Laravel's built-in authentication system. We'll see how to implement authentication and authorization in our application. Stay tuned! If you have any questions or need help, please leave a comment below or refer to the [Laravel Documentation](https://laravel.com/docs/8.x).