检查类别中是否存在帖子不起作用.php, Blade, Laravel

Question

我有一个包含所有类别的视图，通过单击一个类别，用户可以转到该类别。但如果没有这一类的帖子，我想避免去那里。我试着这样做:

@if(($category->id === $category->posts()) !== 0)
<a class="btn btn-success" href="{{ route('category', $category->code)}}">Open</a>
@else
<span class="btn btn-warning">No posts in this category</span>
@endif

posts()在我的范畴模型中是一个雄辩的关系:

public function posts() {
return $this->hasMany(Post::class);
}

但是它不起作用。所有的类别都写在"帖子没有类别"或";Open"。也就是说，检查不能正常工作。

Answer 1

在您的刀片文件检查条件

@if($category->posts_count > 0)
<a class="btn btn-success" href="{{ route('category', $category->code)}}">Open</a>
@else
<span class="btn btn-warning">No posts in this category</span>
@endif

在你的控制器使用withCount方法

$category = Category::withCount('posts')->get();

和在您的类别模型中添加关系，如果没有添加(一对多)

public function posts(){
return $this->hasMany(Post::class);
}

Answer 2

在控制器中你可以做

$category = Category::withCount('posts')->get()

它生成post_count键，您可以在视图

中检查

@if($category->posts_count > 0)
<a class="btn btn-success" href="{{ route('category', $category->code)}}">Open</a>
@else
<span class="btn btn-warning">No posts in this category</span>
@endif

https://laravel.com/docs/8.x/eloquent-relationships counting-related-models

---

更新

$category = Category::withCount('posts')->findOrFail(1)
if($category->posts_count > 1){
return redirect()->back() 
}