php - 将所有数字相加

Question

我有一个这样的数据库：

ID    |    AMOUNT 
1           15.00
2          100.00
3          100.00

我需要将所有金额加在一起。我已经尝试了一些 PHP 数学的东西，但就是不能让它工作。

<?php
$total = mysql_query("SELECT amount FROM payments") 
or die(mysql_error()); 

$grandtotal=   
    while($total1 = mysql_fetch_array( $total )) {

$total1['amount']+


};

?>

Answer 1

SELECT SUM(amount) as sum_amount FROM payments

Answer 2

对于您要完成的特定任务，有两种解决方案：

while($total1 = mysql_fetch_array( $total )) {

$total1['amount']++; //returns Returns $total1['amount'], then increments it by one.

} // <-- semicolon removed

---

正如 Mark Ba​​ker 在评论中建议的那样，您可以在 SQL 查询中使用SUM：

SELECT SUM(amount) AS amount_sum FROM payments