MYSQLi bind_result 返回 null

I am trying to output the variables that I get from the database in my query but nothing is being returned. Using MYSQLi prepared statements.

请看下面的代码:

$stmt = $con->prepare("SELECT first_name, last_name FROM transactions WHERE order_id = ?");
$stmt->bind_param('i', $order_id);
$stmt->execute(); 
$stmt->store_result();
$stmt->bind_result($first_name, $last_name);
$stmt->close();


// Output review live to page 
echo $first_name;

我哪里出错了?

推荐答案

您忘记了获取结果的行.fetch().

  $stmt->bind_result($first_name, $last_name);
  $stmt->fetch();  // ----- > you forget that line to fetch results.
  $stmt->close();