Eloquent ORM
Model Patterns
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Database\Eloquent\Casts\Attribute;
class Post extends Model
{
use HasFactory, SoftDeletes;
protected $fillable = [
'title',
'slug',
'content',
'published_at',
'user_id',
];
protected $casts = [
'published_at' => 'datetime',
'metadata' => 'array',
'is_featured' => 'boolean',
];
// Accessor using new Attribute syntax (Laravel 9+)
protected function title(): Attribute
{
return Attribute::make(
get: fn (string $value) => ucfirst($value),
set: fn (string $value) => strtolower($value),
);
}
// Mutator for computed property
protected function excerpt(): Attribute
{
return Attribute::make(
get: fn () => str($this->content)->limit(100),
);
}
}
Relationships
// One-to-Many
class User extends Model
{
public function posts(): HasMany
{
return $this->hasMany(Post::class);
}
public function latestPost(): HasOne
{
return $this->hasOne(Post::class)->latestOfMany();
}
public function oldestPost(): HasOne
{
return $this->hasOne(Post::class)->oldestOfMany();
}
}
class Post extends Model
{
public function user(): BelongsTo
{
return $this->belongsTo(User::class);
}
// Inverse relationship
public function comments(): HasMany
{
return $this->hasMany(Comment::class);
}
}
// Many-to-Many with Pivot
class User extends Model
{
public function roles(): BelongsToMany
{
return $this->belongsToMany(Role::class)
->withPivot('expires_at', 'assigned_by')
->withTimestamps()
->using(RoleUser::class); // Custom pivot model
}
}
// Has Many Through
class Country extends Model
{
public function posts(): HasManyThrough
{
return $this->hasManyThrough(Post::class, User::class);
}
}
// Polymorphic Relations
class Image extends Model
{
public function imageable(): MorphTo
{
return $this->morphTo();
}
}
class Post extends Model
{
public function images(): MorphMany
{
return $this->morphMany(Image::class, 'imageable');
}
}
// Many-to-Many Polymorphic
class Tag extends Model
{
public function posts(): MorphToMany
{
return $this->morphedByMany(Post::class, 'taggable');
}
public function videos(): MorphToMany
{
return $this->morphedByMany(Video::class, 'taggable');
}
}
Query Scopes
class Post extends Model
{
// Local scope
public function scopePublished($query): void
{
$query->whereNotNull('published_at')
->where('published_at', '<=', now());
}
public function scopePopular($query, int $threshold = 100): void
{
$query->where('views', '>=', $threshold);
}
// Global scope
protected static function booted(): void
{
static::addGlobalScope('active', function ($query) {
$query->where('status', 'active');
});
}
}
// Usage
$posts = Post::published()->popular(500)->get();
// Custom Scope Class
namespace App\Models\Scopes;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Scope;
class AncientScope implements Scope
{
public function apply(Builder $builder, Model $model): void
{
$builder->where('created_at', '<', now()->subYears(10));
}
}
// Apply in model
protected static function booted(): void
{
static::addGlobalScope(new AncientScope);
}
Custom Casts
namespace App\Casts;
use Illuminate\Contracts\Database\Eloquent\CastsAttributes;
class Money implements CastsAttributes
{
public function get($model, string $key, $value, array $attributes): float
{
return $value / 100; // Store cents, return dollars
}
public function set($model, string $key, $value, array $attributes): int
{
return (int) ($value * 100);
}
}
// In model
protected $casts = [
'price' => Money::class,
];
Query Optimization
// Eager Loading (prevent N+1)
$posts = Post::with(['user', 'comments.user'])->get();
// Lazy Eager Loading
$posts = Post::all();
$posts->load('user');
// Eager Load with Constraints
$users = User::with(['posts' => function ($query) {
$query->where('published', true)->orderBy('created_at', 'desc');
}])->get();
// Count relationships efficiently
$posts = Post::withCount('comments')->get();
foreach ($posts as $post) {
echo $post->comments_count;
}
// Exists checks
$users = User::withExists('posts')->get();
// Chunk for large datasets
Post::chunk(100, function ($posts) {
foreach ($posts as $post) {
// Process post
}
});
// Lazy collection for memory efficiency
Post::lazy()->each(function ($post) {
// Process one at a time
});
Model Events
class Post extends Model
{
protected static function booted(): void
{
static::creating(function ($post) {
$post->slug = str($post->title)->slug();
});
static::updating(function ($post) {
if ($post->isDirty('title')) {
$post->slug = str($post->title)->slug();
}
});
static::deleted(function ($post) {
$post->images()->delete();
});
}
}
// Using Observers
namespace App\Observers;
class PostObserver
{
public function creating(Post $post): void
{
$post->user_id = auth()->id();
}
public function updated(Post $post): void
{
cache()->forget("post.{$post->id}");
}
}
// Register in AppServiceProvider
use App\Models\Post;
use App\Observers\PostObserver;
public function boot(): void
{
Post::observe(PostObserver::class);
}
Advanced Queries
// Subqueries
$users = User::select(['id', 'name'])
->addSelect(['latest_post_title' => Post::select('title')
->whereColumn('user_id', 'users.id')
->latest()
->limit(1)
])->get();
// When conditional queries
$posts = Post::query()
->when($search, fn ($query) => $query->where('title', 'like', "%{$search}%"))
->when($category, fn ($query) => $query->where('category_id', $category))
->get();
// Database transactions
DB::transaction(function () {
$user = User::create([...]);
$user->profile()->create([...]);
$user->assignRole('member');
});
// Pessimistic locking
$user = User::where('id', 1)->lockForUpdate()->first();
// Upserts
User::upsert(
[
['email' => 'john@example.com', 'name' => 'John'],
['email' => 'jane@example.com', 'name' => 'Jane'],
],
['email'], // Unique columns
['name'] // Columns to update
);
Performance Tips
- Always eager load relationships - Avoid N+1 queries
- Use chunking for large datasets - Prevent memory exhaustion
- Index foreign keys - Speed up joins
- Use select() to limit columns - Reduce data transfer
- Cache expensive queries - Use Redis/Memcached
- Use database indexing - Add indexes in migrations
- Avoid using model events for heavy operations - Use queues instead
- Use lazy collections - For processing large datasets
