Question

我在分解给定付款金额时遇到问题，我认为我的代码中缺少某些内容。这是我的下表。

如果我支付了5,000，则它将在第一行扣除，剩余的金额将发送到第二行。

//这是付款

$payment = 5000;
$temp = '';

//功能循环

$data = payment_breakdown();
foreach ($data as $row) {

    $amount = $row['AMOUNT'] - $payment."\n";
}

//处理函数每个循环的差异

$temp = $amount;

//金额结果

echo $amount;

//这是我从表中获取数据的功能

function payment_breakdown(){
    $db = database2();
    $query = "SELECT AMOUNT FROM TABLE1";
    $cmd = $db->prepare($query);    
    $cmd->execute();
    $rows = $cmd->fetchAll();
    $db = null;

    return $rows;
}

假设表上的金额是这个

Data From Table | The Payment
        3000    |     3000
        3000    |     2000

Answer 1

您可以在SQL中完成此操作

SELECT 
  amount, 
  paid,
  sum(amount-paid) open
FROM
  payment 
GROUP BY amount, paid 
WITH ROLLUP
HAVING 
  amount IS NULL
  OR paid IS NOT NULL
;

基于数据

INSERT INTO payment (amount, paid)
VALUES 
(3000,3000), 
(3000,2000),
(4000,1000)
;

你得到

amount;paid; open
3000  ;2000; 1000
3000  ;3000; 0
4000  ;1000; 3000
NULL  ;NULL; 4000

或者您可能希望简单地从存款中扣除：

SET @credit := 5000;

SELECT 
  amount, 
  @credit := @credit-amount credit  
FROM payment 
;

SELECT @credit;

但是，在后一种情况下，您应该宁愿将所有付款和要付款的金额存储到数据库表中，然后将它们总计在一起。考虑重构您的数据库结构设计。

如何在表格的每个循环上求和

1 个答案: