php - 访问一个表中不属于其他两个表的数据

Question

//示例数据库

起初 Scholar 有 1,2,3,4,5,6 个 id

Scholar      
Id      
1   
2
3
4
5
6

现在 1 和 2 已在表 Member 下获取

Member 
Id
1 - taken
2 - taken

接下来的 3 和 4 是在表 AddRequest 下获取的

AddRequest
Id
3 - taken
4 - taken

现在 Scholar 表应该只有我想要显示的 ID 5 和 6。

如何使用下面的代码解决此问题

public function ListOrgaScholar($ship_id)
{
    $members = Member::where('ship_id','=',$ship_id)->get();
    $members = $members->toArray();
    $scholar_ids = array_pluck($members, 'scholar_id');
    $scholar_exits = Scholar::whereNotIn('scholar_id', $scholar_ids)->get();

    $requests = AddRequest::where('ship_id','=',$ship_id)->get();
    $requests = $requests->toArray();
    $scholar_ids = array_pluck($requests, 'scholar_id');
    $add_exits = Scholar::whereNotIn('scholar_id', $scholar_ids)->get();   

    if ($scholar_exits == true && $add_exits == true) {

    $scholars = (new Scholar)->newQuery()->select('*');

    $scholars = $scholars->get();
    dd($scholars);
}else{
}
}

dd的结果

Collection {#302 ▼
  #items: array:7 [▼
    0 => Scholar {#305 ▶}
    1 => Scholar {#306 ▶}
    2 => Scholar {#307 ▶}
    3 => Scholar {#308 ▶}
    4 => Scholar {#309 ▶}
    5 => Scholar {#310 ▶}
    6 => Scholar {#311 ▶}
  ]
}

This for Member and AddRequest Table

This for Scholar

Answer 1

在检查了members和addRequests之后，您尝试从Scholar表中选择所有内容，这就是您的原因获取全部六条记录。

我将向 scholar 表添加两个字段，例如 is-member 和 has-request ，并根据以下条件将 bool 值更新为 true诸如 - 当学者转变为成员时，is-member 变为 true 以及当学者添加请求时 has-request 变为 true 或类似事件。这样一来，找到既不是成员(member)也没有任何要求的学者就变得很容易了。

但是就你的情况而言，我认为你应该尝试如下:

public function ListOrgaScholar($ship_id)
{
    $scholar_ids = [];
    $members = Member::where('ship_id','=',$ship_id)->get();
    //$members = $members->toArray();
    //$scholar_ids = array_pluck($members, 'scholar_id');
    //$scholar_exits = Scholar::whereNotIn('scholar_id', $scholar_ids)->get();
    foreach($members as $member){
        $scholar_ids[] = $member->scholar_id;
    }

    $requests = AddRequest::where('ship_id','=',$ship_id)->get();
    //$requests = $requests->toArray();
    //$request_scholar_ids = array_pluck($requests, 'scholar_id');
    //$add_exits = Scholar::whereNotIn('scholar_id', $scholar_ids)->get();
    foreach($requests as $request){
        $scholar_ids[] = $request->scholar_id;
    }   

    $scholars = Scholar::whereNoIn('scholar_id', $scholar_ids)->get();
    dd($scholars);
}