**Single Table Inheritance vs. Multi Table Inheritance with Eloquent: Which is Right for Your Laravel Application?**

Implementing Single Table Inheritance with Laravel's Eloquent

When working with database models, inheritance provides a way to define hierarchies of related entities. However, when choosing between single and multi table inheritance, the latter often emerges as a more efficient and flexible solution.

Single Table Inheritance

While conceptually simpler, single table inheritance requires storing all columns for all types in a single table, leading to potential NULL value proliferation. This can impact database performance, especially with large datasets.

Multi Table Inheritance with Eloquent

Multi table inheritance involves splitting the single table into multiple ones, each corresponding to a specific model type. Laravel's Eloquent framework offers polymorphic relationships to seamlessly manage these relationships.

Post Model

The base class for all post types, Post, represents the shared columns and defines a postable polymorphic relationship:

<code class="php">class Post extends Eloquent {
    public function postable() {
        return $this->morphTo();
    }
}</code>

Question/Article Models

Each specific post type, like Question or Article, extends from Post and defines a morphOne relationship with the base model:

<code class="php">class Question extends Post {
    public function post() {
        return $this->morphOne('Post', 'postable');
    }
}</code>

Usage Examples

• Retrieve all posts: $posts = Post::all();
• Retrieve all questions: $questions = Question::all();
• Retrieve question-specific column from a post: $question_column = $post->postable->question_column;
• Check post type: echo 'Type: '.get_class($post->postable);

Creating a New Question

Creating a new Question requires linking it to the Post table to maintain multi-table inheritance:

<code class="php">$post = new Post();
$post->shared_column = 'New Question Post';
$post->save();

$question = new Question();
$question->question_column = 'My Question';
$question->save();

$question->post()->save($post);</code>

Although multi-table inheritance involves more complexity, it offers a cleaner database structure, improves performance, and enables greater flexibility for modeling complex relationships.

For comprehensive tutorials on multi-table inheritance in Laravel, refer to the resources provided in the original question answer.

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