“三路"使用口才的多对多关系

问题描述

我有一个简单的数据库设置:用户，组，页面-每个都有很多.参见图: http://i.imgur.com/oFVsniH.png

I have a simple database setup: Users, Groups, Pages - each are many to many.See diagram: http://i.imgur.com/oFVsniH.png

现在，我有一个可变的用户ID($ id)，并希望以此返回用户可以访问的页面的列表，这显然是因为在所有表上都是多对多的.

Now I have a variable user id ($id), and with this I want to get back a list of the pages the user has access to, distinctly, since it's many-to-many on all tables.

我已经像这样设置了我的主要模型:

I've setup my main models like so:

class User extends Eloquent {
    protected $table = 'ssms_users';

    public function groups()
    {
        return $this->belongsToMany('Group', 'ssms_groups_users', 'user_id','group_id');
    }

}
class Group extends Eloquent {
    protected $table = 'ssms_groups';

    public function users()
    {
        return $this->belongsToMany('User', 'ssms_groups_users', 'user_id','group_id');
    }

    public function pages()
    {
        return $this->belongsToMany('Page', 'ssms_groups_pages', 'group_id','page_id');
    }

}
class Page extends Eloquent {
    protected $table = 'ssms_pages';

    public function groups()
    {
        return $this->belongsToMany('Group', 'ssms_groups_pages', 'group_id','page_id');
    }

}

只需执行以下操作即可获取用户所属的组:

I can get the groups the user belongs to by simply doing:

User::with('groups')->first(); // just the first user for now

但是我完全迷失了如何通过一个查询获得用户(清晰地)访问的页面?

However I'm totally lost on how to get the pages the user has access to (distinctly) with one query?

我相信SQL将会是这样的:

I believe the SQL would be something like:

select DISTINCT GP.page_id
from GroupUser GU
join GroupPage GP on GU.group_id = GP.group_id
where GU.user_id = $id

任何人都可以帮忙吗?

谢谢

推荐答案

您之前是否尝试过这种方法?

Have you tried something like this before?

$pages = User::with(array('groups', 'groups.pages'))->get();

快速加载可能是解决您问题的方法:快速加载

Eager loading might be the solution to your problem: eager loading

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