Laravel命令通过关系

Question

我正在查看特定帖子的作者发布的所有评论.

foreach($post->user->comments as $comment)
    {
        echo "<li>" . $comment->title . " (" . $comment->post->id . ")</li>";
    }

这给了我

I love this post (3)
This is a comment (5)
This is the second Comment (3)

我如何通过post_id订购,以便上面的列表被命令为3,3,5

Answer 1

可以扩展与查询函数的关系:

<?php
public function comments()
{
    return $this->hasMany('Comment')->orderBy('column');
}

[评论后编辑]

<?php
class User
{
    public function comments()
    {
        return $this->hasMany('Comment');
    }
}

class Controller
{
    public function index()
    {
        $column = Input::get('orderBy', 'defaultColumn');
        $comments = User::find(1)->comments()->orderBy($column)->get();

        // use $comments in the template
    }
}

默认用户模型+简单控制器示例; 获取注释列表时,只需根据Input :: get()应用orderBy().(一定要做一些输入检查;))

Answer 2

我相信你也可以这样做：

$sortDirection = 'desc';

$user->with(['comments' => function ($query) use ($sortDirection) {
    $query->orderBy('column', $sortDirection);
}]);

这允许您在每个相关评论记录上运行任意逻辑。你可以在里面放一些东西，比如：

$query->where('timestamp', '<', $someTime)->orderBy('timestamp', $sortDirection);

Answer 3

尝试这个解决方案。

$mainModelData = mainModel::where('column', $value)
    ->join('relationModal', 'main_table_name.relation_table_column', '=', 'relation_table.id')
    ->orderBy('relation_table.title', 'ASC')
    ->with(['relationModal' => function ($q) {
        $q->where('column', 'value');
    }])->get();

例子：

$user = User::where('city', 'kullu')
    ->join('salaries', 'users.id', '=', 'salaries.user_id')
    ->orderBy('salaries.amount', 'ASC')
    ->with(['salaries' => function ($q) {
        $q->where('amount', '>', '500000');
    }])->get();

join()您可以根据数据库结构更改列名称。

Answer 4

使用sortBy...可能会有所帮助。

$users = User::all()->with('rated')->get()->sortByDesc('rated.rating');