Php 购物车系统中的foreach和while错误

我正在用paypal编程一个购物车系统，我与foreach有麻烦，foreach将不同的产品设置为paypal形式。代码如下：

public function GetUserCart(){  //we get the items in the user cart
 $mysqli = $this->connection();
 $data = $mysqli->query("SELECT * FROM carrito WHERE usuario_id='$this->username_id'");
 return $data;
    }
//we get the values of the products
public function GetPictureData($id_product,$picture_column){
$mysqli = $this->connection();
$validacion = $mysqli->query("SELECT * FROM pinturas WHERE id='$id_product' LIMIT 1");
$data = $validacion->fetch_assoc();
return $data[$picture_column];
    }


$itemstopaypalname=''; //name of the product
 $itemstopaypalprice=''; //price of the product
 //we get the items in the user cart
 $querys = $this->GetUserCart();
 $dataset = array(); //this is for use outside a while
 while ($data = $querys->fetch_array()) {   
 $dataset[] = $data;
 }
 $cart .= '<input type="hidden" name="notify_url" value="'.$this->url.'files/libs/paypal.php">
<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="'.$this->email().'">';
 $num = 1;
 foreach($dataset as $k => $v){  //this is where im having troubles
 $itemstopaypalname.=$this->GetPictureData($v['producto_id'],"titulo"); 
 $itemstopaypalprice.=$this->GetPictureData($v['producto_id'],"price"); 
 $cart .= '<input type="hidden" name="item_name_'.$num.'" value="'. $itemstopaypalname.'">';
 $cart .= '<input type="hidden" name="amount_'.$num.'" value="'. $itemstopaypalprice.'">';
 $num = $num + 1; 
 } 

因此，当第二个和第三个产品分别重复第一个和第二个产品时：

<input type="hidden" name="item_name_1" value="mono">
<input type="hidden" name="amount_1" value="567">
<input type="hidden" name="item_name_2" value="monocosos">
<input type="hidden" name="amount_2" value="5674678">
<input type="hidden" name="item_name_3" value="monocososImage Upload">
<input type="hidden" name="amount_3" value="56746782450">

因此，您可以看到每个数量中有567个重复，我如何解决这个问题？

$itemstopaypalname.=这也将连接以前的字符串

试一试

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$itemstopaypalname=$this->GetPictureData$v['producto_id'，titulo$itemstopaypalprice=$this->GetPictureData$v['producto_id'，price

$itemstopaypalname.=这也将连接以前的字符串。请尝试$itemstopaypalname=$this->GetPictureData$v['producto_id'，titulo$itemstopaypalprice=$this->GetPictureData$v['producto_id'，price；很高兴知道。。请接受答案好了，谢谢你的帮助