我如何執行一個操作結果mysql查詢結果沒有循環/ foreach

Question

$users = User:all(); 
//User:all() is based on the laravel eloquent model , it's just similar to 'select * from user' query 

$total_spend_amount = 0; 

    foreach($users as $user) 
    { 
     $total_spend_amount += $user->spend_amount; 
    } 

    echo "Total spend amount :".$total_spend_amount; 

//Note: In this simple example i just want to sum of all the spend_amount 

以上只是一個簡單的例子，我如何做一些算法的結果查詢沒有循環/ foreach在PHP？

User::all()->sum('spend_amount'); // this is the answer below and this is correct 
//but how about if i want the 'specific algorithm' to be performed on the resulted query instead of sum? 

但怎麼樣，如果我想在「特定算法」要對查詢結果，而不是總和進行？

Answer 1

我不知道有關語法，但使用雄辯與

User::all()->sum('spend_amount'); 

或

User::all()->select(DB::raw("SUM(spend_amount)")->get(); 

Answer 2

Laravel提供sum()嘗試在默認情況。

$total_spent_amount = DB::table('users')->all()->sum('spent_amount`);