如何在没有 looping/foreach 的情况下对结果 mysql 查询结果执行操作

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

以上只是一个简单的例子，我如何在 php 中没有 looping/foreach 的情况下对结果查询执行一些算法？

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?

但是如果我希望对结果查询执行 'specific algorithm' 而不是求和呢？

Answer 1

我不确定语法，但请尝试使用

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 looping/foreach 的情况下对结果 mysql 查询结果执行操作

How do i perform an operation on resulted mysql query result without looping/foreach

php

laravel

php-5.6

php-7

laravel-eloquent