Question

$connect = mysqli_connect("localhost", "root", "", "hempbag_db") or die("Connection failed");

foreach($a as $b){ 
    foreach($b as $c){
        $query5 = "SELECT P_price tbl_products WHERE PID='".$c['PID']."' ";
        $get_price = mysqli_query($connect, $query5);
        $get_price1 = mysqli_fetch_assoc($get_price); 
        $price = ($get_price1['P_price'])+ $price + 0; // This does not add
    }
}

$price不会仅添加循环内数据的最后一个值。

如何添加它们？

我还用过：

$price = ($get_price1['P_price'])+0;
$new_price += $price;

仍然失败。
谢谢！

Answer 1

尝试一下：$total_price是价格的总和。

$connect = mysqli_connect("localhost", "root", "", "hempbag_db") or die("Connection failed");

$total_price = 0;
foreach($b as $c) {
    $query5 = "select P_price from tbl_products where PID='".$c['PID']."' ";
    $get_price = mysqli_query($connect, $query5);
    $get_price1 = mysqli_fetch_assoc($get_price);
    $total_price += $get_price1['P_price'];
}

echo $total_price;

Answer 2

在遍历数组之前初始化$price。

$connect = mysqli_connect("localhost", "root", "", "hempbag_db") or die("Connection failed");

$price = 0;
foreach($b as $c)
{
  $query5 = "select P_price from tbl_products where PID='".$c['PID']."' ";
  $get_price = mysqli_query($connect, $query5);
  $get_price1 = mysqli_fetch_assoc($get_price); 
  $price = ($get_price1['P_price'])+$price;
  // other way (highly recommended)
  $price += ($get_price1['P_price']);
}

在每个PHP中添加总和

2 个答案: