Eager Load Relationships Conditionally with loadMissing()

Use loadMissing() to eager-load relationships only if they have not already been loaded on the model instance.

When passing models through service layers, notification handlers, or Blade components, calling $post->load('author') forces a new database query even if author was already eager-loaded upstream.

The loadMissing() method checks if the relationship is already loaded before executing any query.

Basic Usage

use App\Models\Post;

public function formatPost(Post $post): array
{
    // Executes query ONLY IF 'author' and 'comments' are not already loaded
    $post->loadMissing(['author', 'comments.user']);

    return [
        'title'  => $post->title,
        'author' => $post->author->name,
        'count'  => $post->comments->count(),
    ];
}

Difference Between load() and loadMissing()

• $model->load('relation'): Always executes a new database query to reload the relation.
• $model->loadMissing('relation'): Checks $model->relationLoaded('relation') first, querying only if missing.

Summary

• Prevents duplicate database queries across multi-layered services.
• Supports nested relationships using dot notation (comments.user).
• Ideal for helper functions and formatting pipelines.