用PHP总结所选列的总和，我的代码是对的吗？

Question

我正在为“价格”栏目的总销售额创建一个代码，我做得对吗???

public function gettotalsales()
{
        $stmt = $this->conn->prepare("Select SUM(Price) From tbl_orderlist where Price != '' ");
        $stmt->execute();
        return $stmt;
}

Database img

Answer 1

您只需编写以下行

Select SUM(Price) From tbl_orderlist

Answer 2

Select SUM(Price) From tbl_orderlist