我怎样才能只在Laravel中的“ hasManyThrough”关系中选择一个列？

Question

Building::with('user_through_building')
                      ->where('id', $building_id)
                      ->pluck('user_through_building.id');

我一直在收到错误Unknown column 'user_through_building.id' in 'field list' (SQL: select 'user_through_building'.'id' from 'buildings' where 'id' = 20 and 'buildings'.'deleted_at' is null)

Answer 1

试试这个

Building::with(['user_through_building' => function($q){ 
     $q->pluck('id'); 
}])->where('id', $building_id)

Answer 2

// Retrieve all buildings that have at least one user_through_building
return Building::has('user_through_building')->get(['id']);

// Returns all Buildings, along with user_through_building' IDs
return Building::with('user_through_building:id')->get();