laravel%3aeloquent-relationships（Laravel 3aeloquent relationships 搜索）

Eloquent Relationships and Loading

Model relationships express your domain; load only what you need.

Commands

# Typical loading
Post::with(['author', 'tags'])->withCount('comments')->paginate(20);

# Constrained eager loading
User::with(['posts' => fn($q) => $q->latest()->where('published', true)])->find($id);

# Pivot ops (many-to-many)
$post->tags()->sync([1,2,3]);       // atomic replace
$post->tags()->syncWithoutDetaching([4]);

# Chunking large reads
Order::where('status', 'open')->lazy()->each(fn($o) => ...);

Patterns

• See laravel:performance-eager-loading for N+1 detection and measurement
• Use whereHas() / has() to filter by related existence
• Prefer withCount, withSum, withMax for simple aggregates
• Apply global / local scopes for recurring constraints
• Keep relationship names consistent and pluralized where appropriate