php - 尝试从函数中检索 int 类型并将其与 $_Get 值进行比较(mysql PHP)

Question

我尝试从数据库中检索 int 类型并将其与 $_Get value 进行比较

这是用户单击按钮时的代码

if(isset($_GET['btn_placeorder']))
{


$Quantity_Ordered=(int)$_GET['Quantity_Ordered'];


**# retreivng another value from function to compare it as integer**
$number= (int)$auth_user->Blood_Bankavaliable        ($Blood_BankID,$Type_Ordered);

  try
   {

     if ($Type_Ordered=="" || $Quantity_Ordered=="")
    {
    $error[] = "Valid data is required!";   
}

else if($Quantity_Ordered >$number) {
    $error[] = "This Number is not avaliable in our Stock !";
}

这是该函数的代码

function  Blood_Bankavaliable($blood_bankID,$Type_Ordered) {
      global $conn;
# query for getting the value from the database
    $query = "select sum(Blood_quantity) as d from Donor_Blood_Bank   where     Blood_Type=$Type_Ordered and blood_bankID= $blood_bankID";
  try {

    $statement = $this->conn->prepare($query);
    $statement->execute();
   $result = $statement->fetchall;

   return $result;
} catch(PDOException $e)
    {
        echo $e->getMessage();
    }

}

我不知道我的代码有什么问题，有什么帮助吗？

Answer 1

首先，它应该是 $result = $statement->fetchAll();(函数或方法)，而不是 $result = $statement->fetchall (属性)。

第二，请阅读manul , fetchall() 返回一个数组。因此你不能直接将其转换为 int 。运行 print_r( $auth_user->Blood_Bankavaliable($Blood_BankID,$Type_Ordered) ); 查看您自己。