Many-to-Many Relationships: Pivot Tables the Right Way

Many-to-many relationships are common: - users belong to many roles - posts have many tags - products belong to many categories This requires a pivot table. ## Example: posts and tags Tables: - posts - tags - post_tag (pivot) ## Relationship definitions Post model: ```php public function tags() { return $this->belongsToMany(Tag::class); } ``` Tag model: ```php public function posts() { return $this->belongsToMany(Post::class); } ``` ## Attach tags ```php $post->tags()->attach([1, 2, 3]); ``` ## Sync tags ```php $post->tags()->sync([2, 4]); ``` ## Graph: relationship structure ```mermaid flowchart LR A[posts] --> C[post_tag pivot] B[tags] --> C ``` In the next tutorial, we will optimize many-to-many queries using eager loading and pivot data.