購物車總計含運費

Question

我一直試圖根據產品數量找出總價，我正在數據庫中保存數量和價格，以下是我用來找出總價的查詢

SELECT SUM( price * quantity ) AS subtotal, SUM( quantity ) AS qty
FROM  `cart` 
WHERE user
IN (

SELECT id
FROM users
WHERE email =  'test'
)

現在我想要的是，我需要添加運費，如果數量是1-5，則運費將是50，如果數量是6-10，則運費將是100，等等。

我怎樣才能做到這一點？ 這是我正在嘗試但錯誤的！ 請給我找到解決方案。

 $subtotalquery=" SELECT SUM( price * quantity ) as subtotal, SUM(quantity) as qty FROM  `cart` WHERE user IN  (select id from users where email='$user_check')";
                                $t_con=$conn->query($subtotalquery);
                                $subtotalrow = $t_con->fetch_assoc();

                                $subtotal= $subtotalrow['subtotal'];
                                $qty= $subtotalrow['qty'];
                                if($qty>=5)
                                {
                                    $shipping=50 ;

                                    $ithship=$subtotalrow+($shipping);

                                }else
                                {
                                $shipping=50*2 ;

                                    $ithship=$subtotalrow+($shipping*2);
}

Answer 1

您可以改用CASE語句

SELECT SUM(price * quantity) AS subtotal,
SUM(quantity) as quantity, 
CASE 
  WHEN SUM(quantity) <=5 THEN
  50
  WHEN SUM(quantity) BETWEEN 6 AND 10 THEN
  100
  ELSE
  150
  END as ShippingCharge
from  `cart` 
WHERE user
IN 
(
SELECT id
FROM users
WHERE email =  'test'
)

>>>演示<<<

Answer 2

嘗試以下代碼，您需要將運費加到小計中

if($qty<=5)
{
    $shipping=50 ;
}else
{
$shipping=50*2 ;
}
$ithship=$subtotal+$shipping; // add to  subtotal

編輯

如果要增加每5個以上數量的運費。 嘗試下面的代碼

$qty= $subtotalrow['qty'];
$incr  = ceil($qty/5);
$shipping = $incr*50;
echo $shipping;

編輯您也可以使用sql查詢來實現：

SELECT SUM( price * quantity ) as subtotal, SUM(quantity) as qty, ((ceil(SUM(quantity)/5))*50) as ShippingCharge FROM  `cart` WHERE user IN  (select id from users where email='$user_check');

DEMO