采摘渴望加载Laravel 5.2

Posted 2021-04-09

在使用Laravel 5.2进行查询时，如何获取急切加载的关系？

$users = User::with(['posts' => function($query){
       $query->pluck('id');
       }])->get();

我希望响应只是用户帖子ID的数量，如下所示：

[{user: Blabel, posts: [24,25,26]},
 {user: Kraker, posts: [75,76,77]}]

我现在得到的是帖子表中的所有字段：

[{user:Blabel,
  posts:[{id:24, name: "blabla", text: "bleble"},
         {id:25, name: "blablabla", text: "blebleble"},
         {id:26, name: "blablablo", text: "blebleblo"},
         ...
        ]},
  {user:Kraker,
   posts:[{id:75, name: "krakra", text: "krekre"},
          {id:76, name: "krakrakra", text: "krekrekre"},
          {id:77, name: "krokro", text: "krekrekro"},
          ...
         ]}

我可以在Eager Loading Constraint中使用pluck吗？这是同一个问题：Pluck Eager Loading Laravel 5.4，但我没有找到成功的答案。

答案

您必须在查询后拔出ID：

$users = User::with(['posts' => function($query){
   $query->select('id', 'user_id'); // assuming it's a HasMany relationship
}])->get();
$users = $users->toArray();
foreach($users as $i => $user) {
    $users[$i]['posts'] = collect($user['posts'])->pluck('id');
}