問題描述

我正在學習 Laravel.我使用 Eloquent ORM 刪除方法，但得到不同的結果.不是真或假而是空.我設置了一個資源路由，在UsersController中有一個destroy方法.

Hi I am studying laravel. I use Eloquent ORM delete method but I get a different result.Not true or false but null. I set an resource route and there is a destroy method in UsersController.

public function destroy($id){

  $res=User::find($id)->delete();
  if ($res){
    $data=[
    'status'=>'1',
    'msg'=>'success'
  ];
  }else{
    $data=[
    'status'=>'0',
    'msg'=>'fail'
  ];
  return response()->json($data);

但是我總是得到響應{"status":"0","msg":"failed"}，數據庫中的記錄被刪除了.

But I always get a response {"status":"0","msg":"failed"},the record in the database is deleted.

然后我使用 dd($res) .它在頁面中顯示為空.

Then I use dd($res) .It shows null in the page.

但是從我學習的課程中，它返回一個布爾值 true 或 false.

But from the course I learn it returns a boolean value true or false.

我的代碼有錯誤嗎?

你能告訴我從數據庫中刪除數據時可以得到布爾結果的其他方法嗎?

Can you tell me some other method that I can get a boolean result when I delete data from database?

推薦答案

delete 之前，laravel 有幾個方法.

Before delete , there are several methods in laravel.

User::find(1) 和 User::first() 返回一個實例.

User::find(1) and User::first() return an instance.

User::where('id',1)->get 和 User::all() 返回一個實例集合.

User::where('id',1)->get and User::all() return a collection of instance.

在模型實例上調用 delete 將返回 true/false

call delete on an model instance will returns true/false

$user=User::find(1);
$user->delete(); //returns true/false

對實例集合調用 delete 將返回一個數字，表示已刪除的記錄數

call delete on a collection of instance will returns a number which represents the number of the records had been deleted

//assume you have 10 users, id from 1 to 10;
$result=User::where('id','<',11)->delete(); //returns 11 (the number of the records had been deleted)

//lets call delete again
$result2=User::where('id','<',11)->delete(); //returns 0 (we have already delete the id<11 users, so this time we delete nothing, the result should be the number of the records had been deleted(0)  ) 

還有其他刪除方法，你可以調用destroy作為模型靜態方法，如下所示

Also there are other delete methods, you can call destroy as a model static method like below

$result=User::destroy(1,2,3);
$result=User::destroy([1,2,3]);
$result=User::destroy(collect([1, 2, 3]));
//these 3 statement do the same thing, delete id =1,2,3 users, returns the number of the records had been deleted

還有一點，如果你是 laravel 的新手，你可以使用 php artisan tinker 來查看結果，這樣效率更高，然后 dd($result) , print_r($result);

One more thing ,if you are new to laravel ,you can use php artisan tinker to see the result, which is more efficient and then dd($result) , print_r($result);

這篇關于laravel Eloquent ORM delete() 方法的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！