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

上面只是一个简单的例子，如何在没有循环/ foreach的情况下对结果查询做一些算法？

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?

但是，如果我想要特定算法＆＃39;要对结果查询执行而不是求和？

Answer 1

我不确定语法，但尝试使用

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

或

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

Answer 2

Laravel默认使用eloquent提供sum()。

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

如何在没有循环/ foreach的情况下对生成的mysql查询结果执行操作

2 个答案: