Eloquent Best Practices

Query Optimization

Always Eager Load Relationships

// ❌ N+1 Query Problem
$posts = Post::all();
foreach ($posts as $post) {
    echo $post->user->name; // N additional queries
}

// ✅ Eager Loading
$posts = Post::with('user')->get();
foreach ($posts as $post) {
    echo $post->user->name; // No additional queries
}

Select Only Needed Columns

// ❌ Fetches all columns
$users = User::all();

// ✅ Only needed columns
$users = User::select(['id', 'name', 'email'])->get();

// ✅ With relationships
$posts = Post::with(['user:id,name'])->select(['id', 'title', 'user_id'])->get();

Use Query Scopes

// ✅ Define reusable query logic
class Post extends Model
{
    public function scopePublished($query)
    {
        return $query->where('status', 'published')
                    ->whereNotNull('published_at');
    }
    
    public function scopePopular($query, $threshold = 100)
    {
        return $query->where('views', '>', $threshold);
    }
}

// Usage
$posts = Post::published()->popular()->get();

Relationship Best Practices

Define Return Types

use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;

class Post extends Model
{
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }
    
    public function comments(): HasMany
    {
        return $this->hasMany(Comment::class);
    }
}

Use withCount for Counts

// ❌ Triggers additional queries
foreach ($posts as $post) {
    echo $post->comments()->count();
}

// ✅ Load counts efficiently
$posts = Post::withCount('comments')->get();
foreach ($posts as $post) {
    echo $post->comments_count;
}

Mass Assignment Protection

class Post extends Model
{
    // ✅ Whitelist fillable attributes
    protected $fillable = ['title', 'content', 'status'];
    
    // Or blacklist guarded attributes
    protected $guarded = ['id', 'user_id'];
    
    // ❌ Never do this
    // protected $guarded = [];
}

Use Casts for Type Safety

class Post extends Model
{
    protected $casts = [
        'published_at' => 'datetime',
        'metadata' => 'array',
        'is_featured' => 'boolean',
        'views' => 'integer',
    ];
}

Chunking for Large Datasets

// ✅ Process in chunks to save memory
Post::chunk(200, function ($posts) {
    foreach ($posts as $post) {
        // Process each post
    }
});

// ✅ Or use lazy collections
Post::lazy()->each(function ($post) {
    // Process one at a time
});

Database-Level Operations

// ❌ Slow - loads into memory first
$posts = Post::where('status', 'draft')->get();
foreach ($posts as $post) {
    $post->update(['status' => 'archived']);
}

// ✅ Fast - single query
Post::where('status', 'draft')->update(['status' => 'archived']);