我对Laravel的hasManyThrough关系（L5.2）有一些问题。

我有用户和组，而不是一个标准的连接表或一个定制的数据透视模型，我使用另一个有说服力的模型称为GroupMembership来链接这两者。以下是课程的相关部分：

class User extends Model {

    use SoftDeletes;

    protected $primaryKey = 'user_id';

    public function groupMemberships() {
        return $this->hasMany(GroupMembership::class);
    }
}


class GroupMembership extends Model {

    protected $primaryKey = 'group_membership_id';

    public function user() {
        return $this->belongsTo(User::class);
    }

    public function group() {
        return $this->belongsTo(Group::class);
    }
}


class Group extends Model {

    use SoftDeletes;

    protected $primaryKey = 'group_id';

    public function groupMemberships() {
        return $this->hasMany(GroupMembership::class);
    }

    public function users() {
        return $this->hasManyThrough(User::class, GroupMembership::class,
            'group_id', 'user_id', 'group_id'
        );
    }
}

我的问题是$组-

select `users`.*, `group_memberships`.`group_id` from `users` 
inner join `group_memberships`
    on `group_memberships`.`group_membership_id` = `users`.`user_id`
where `group_memberships`.`group_id` = '10'
and `users`.`deleted_at` is null

在该查询中，内部联接条件是错误的。而不是组成员身份。group\u membership\u id，它实际上应该是group\u membership。用户id。

我做错了什么？