Laravel 递归关系

I'm working on a project in Laravel. I have an Account model that can have a parent or can have children, so I have my model set up like so:

public function immediateChildAccounts()
{
    return $this->hasMany('Account', 'act_parent', 'act_id');
}

public function parentAccount()
{
    return $this->belongsTo('Account', 'act_parent', 'act_id');
}

This works fine. What I want to do is get all children under a certain account. Currently, I'm doing this:

public function allChildAccounts()
{
    $childAccounts = $this->immediateChildAccounts;
    if (empty($childAccounts))
        return $childAccounts;

    foreach ($childAccounts as $child)
    {
        $child->load('immediateChildAccounts');
        $childAccounts = $childAccounts->merge($child->allChildAccounts());
    }

    return $childAccounts;
}

这也有效，但我不得不担心它是否慢.这个项目是我们在工作中使用的旧项目的重写.我们将有数千个帐户迁移到这个新项目.对于我拥有的少数几个测试帐户，这种方法不会带来性能问题.

有更好的解决方案吗？我应该运行一个原始查询吗？Laravel有办法处理吗？

In summary

A -> B -> D
|--> C -> E
     |--> F 
G -> H

If I run A->immediateChildAccounts(), I should get {B, C}
If I run A->allChildAccounts(), I should get {B, D, C, E, F} (order doesn't matter)

Again, my method works, but it seems like I'm doing way too many queries.

另外，我不确定在这里问这个是否合适，但这是相关的.如何获得包含don't个子帐户的所有帐户的列表？所以基本上与上述方法相反.这样，用户就不会试图给一个帐户指定一个已经是其子帐户的父帐户.使用上面的图表，我想要(在伪代码中):

Account::where(account_id not in (A->allChildAccounts())). So I would get {G, H}

谢谢你的真知灼见.