laravel Eloquent ORM delete() 方法

发布于06月09日

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);

但我总是得到一个响应{"status":"0"，"msg":"failed"}，数据库中的记录被删除.

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

但我从课程中了解到，它返回布尔值true或false.

我的代码有错误吗？

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

推荐答案

Before delete , there are several methods in laravel.

User::find(1)和User::first()返回一个实例.

User::where('id',1)->get和User::all()返回实例的集合.

call delete on an model instance will returns true/false

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

对实例集合调用delete将返回一个数字，该数字表示已删除的记录数

//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)  )

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

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);