MySQL行数据的乘法

Question

我希望能够将所有价格乘以我的数据库,然后将总数乘以10.

下面的代码执行添加而不是乘法

<?php
$d = $_GET['d'];
$con = mysql_connect("localhost","username","password");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
mysql_select_db("databasename", $con);//

$sql= "SELECT SUM(prices) FROM tablename WHERE Date = '$d' AND Prices >0.20 AND Type= 'sold'";
$results = mysql_query($sql);
$row = mysql_fetch_array($results);
echo $row[0]*10;


mysql_close($con);
?> 

例

id prices
1   25
2   36
3   45

那就是我要25*36*45*10而不是25 + 36 + 45*10

希望有人可以提供帮助

Answer 1

这将有效,有限制(数字应该只是正数):

SELECT 10 * EXP(SUM(LOG(prices))) AS result
FROM tablename 
WHERE ...

thnx应该去Napier和他的奇妙发明,logarithms