Php （Laravel Elount）获取类别和所有嵌套子类别的帖子

我想检索所选类别和所有嵌套子类别的所有帖子。我的意思是这样的：

[id= 1]-Category 1
[id= 7]--Category 1.1
[id=12]---Category 1.1.1
[id=13]---Category 1.1.2
[id= 9]--Category 1.2
[id= 3]-Category 2

首先，我尝试递归地获取所选类别和所有嵌套子类别的所有ID，然后使用这些类别ID检索帖子

我在controller中编写了方法

getSubcategoriesIds（$category）

，它实际上给了我想要的东西，但它返回了带有重复ID的数组。例如，类别1我得到：

array:10 [
    0 => 1
    1 => 7
    2 => 1
    3 => 7
    4 => 12
    5 => 1
    6 => 7
    7 => 12
    8 => 13
    9 => 9
]

如何改进返回没有重复ID的方法？ 或者也许有更好的方法来恢复这些帖子

$subcategoriesIds = array:10 [
    0 => 1
    1 => 7
    2 => 1
    3 => 7
    4 => 12
    5 => 1
    6 => 7
    7 => 12
    8 => 13
    9 => 9
]

这是我的档案：

Model Category.php:

class Category extends Model {

    public function parent() {
        return $this->belongsTo('App\Category', 'parent_id');
    }

    public function children() {
        return $this->hasMany('App\Category', 'parent_id');
    }

    public function subcategories() {
        return $this->children()->with('subcategories');
    }

    public function parents() {
        return $this->parent()->with('parents');
    }

    public function posts(){
        return $this->hasMany('App\Post');
    }
}

public function show($id)
{
    $ids =$this->getSubcategoriesIds(Category::with('subcategories')->where('id', $id)->first()));
    $posts = Post::whereIn('category_id', $ids)->get();
    return view('post.index', compact('posts'));
}

public function getSubcategoriesIds($category) {
    $array = [$category->id];
    if(count($category->subcategories) == 0) {
        return $array;
    } 
    else  {
        foreach ($category->subcategories as $subcategory) {
            array_push($array, $subcategory->id);
            if(count($subcategory->subcategories)){
                $array = array_merge($array, $this->getChildren($subcategory->subcategories, $array));
            }
        }
        return $array;
    }
}

public function getChildren($subcategories, $array) {
    foreach ($subcategories as $subcategory)  {
        array_push($array, $subcategory->id);
        if(count($subcategory->subcategories)){
            return $array = array_merge($array, $this->getChildren($subcategory->subcategories, $array));
        }
        return $array;
    }
}

PostController.php:

class Category extends Model {

    public function parent() {
        return $this->belongsTo('App\Category', 'parent_id');
    }

    public function children() {
        return $this->hasMany('App\Category', 'parent_id');
    }

    public function subcategories() {
        return $this->children()->with('subcategories');
    }

    public function parents() {
        return $this->parent()->with('parents');
    }

    public function posts(){
        return $this->hasMany('App\Post');
    }
}

public function show($id)
{
    $ids =$this->getSubcategoriesIds(Category::with('subcategories')->where('id', $id)->first()));
    $posts = Post::whereIn('category_id', $ids)->get();
    return view('post.index', compact('posts'));
}

public function getSubcategoriesIds($category) {
    $array = [$category->id];
    if(count($category->subcategories) == 0) {
        return $array;
    } 
    else  {
        foreach ($category->subcategories as $subcategory) {
            array_push($array, $subcategory->id);
            if(count($subcategory->subcategories)){
                $array = array_merge($array, $this->getChildren($subcategory->subcategories, $array));
            }
        }
        return $array;
    }
}

public function getChildren($subcategories, $array) {
    foreach ($subcategories as $subcategory)  {
        array_push($array, $subcategory->id);
        if(count($subcategory->subcategories)){
            return $array = array_merge($array, $this->getChildren($subcategory->subcategories, $array));
        }
        return $array;
    }
}

---

您的问题：如何改进返回ID而不重复的方法？或者也许有更好的方法来恢复这些帖子

$subcategoriesIds = array:10 [
    0 => 1
    1 => 7
    2 => 1
    3 => 7
    4 => 12
    5 => 1
    6 => 7
    7 => 12
    8 => 13
    9 => 9
]

我的答案是：

collect（$subcategoriesIds）->unique（）->all（）

---

查看Laravel Collection Unique

我在递归方法中发现了问题。我不应该将

$array

传递给递归方法

getChildrenIds（）

以下是我的解决方案（通过一些重构）：

现在

$this->getCategoriesID（Category:：with（'subcategories'）->where（'id'，1）->first（）返回：

array:10 [
0 => 1
1 => 7
2 => 12
3 => 13
4 => 9
]

我知道我可以从数组中获得唯一的项，但我认为我在递归方法中做了一些错误，并将重复项放到数组中，但我不知道我的方法有什么问题。