php - 从 mysql 转换为 PDO 用户名确认问题

Question

如何将此 mysql 转换为 PDO？我在尝试获取验证用户名是否已存在的代码时遇到问题。

//Check if user already exists

$u_check = mysql_query("SELECT username FROM users WHERE username='$un'");

//Count the amount of rows where username = $un

$check = mysql_num_rows($u_check);



if ($check == 0) {

Answer 1

您可能希望使用 prepared statement 来执行此操作

$u_check = $pdo->prepare("SELECT username FROM users WHERE username= :username");
$u_check->execute(array(':username' => $un));
if($u_check->rowCount()) {