如何使用 pdo 在一个查询中对两个值进行 rowCount？

Question

我正在尝试创建一个注册页面，并且需要验证用户名和电子邮件是否已经退出。如果我在两个查询中执行此操作，它可以正常工作，但切换到一个查询，则它无法正常工作，有时它不会验证值之一。我尝试如下，但它不能正常工作，有时它不验证电子邮件或用户名：  $uname = $_POST['username'];  $email = $_POST['email'];    $sql = "SELECT uid FROM users WHERE username = :username OR email = :email";    $stmt1 = $pdo->prepare($sql);    $stmt1->bindParam(":username", $uname, PDO::PARAM_STR);    $stmt1->bindParam(":email", $email, PDO::PARAM_STR);    $stmt1->execute();    if($stmt1->rowCount() == 1){    $rows = $stmt1->fetch();      if($rows['username'] == 1){        $errors['username'] = "Username already in use.";      }else{        $username = $uname;      }      if($rows['email'] == 1){        $errors['email'] = "Email already in use.";      }else{        $email= $email;      }    }    unset($stmt1);

Answer 1

rowCount当用户名或电子邮件匹配时，方法返回 >= 1 条记录。试试那个代码：

$username = $_POST['username'];

$email = $_POST['email'];

$errors = array();

$sql = "SELECT username, email FROM users WHERE username = :username OR email = :email";

$stmt1 = $pdo->prepare($sql);

$stmt1->bindParam(":username", $username, PDO::PARAM_STR);

$stmt1->bindParam(":email", $email, PDO::PARAM_STR);

$stmt1->execute();

if($stmt1->rowCount() > 0){

    $rows = $stmt1->fetchAll();

    foreach($rows as $row) {

        if($row['username'] === $username) {

            $errors['username'] = "Username already in use.";

        }

        if($row['email'] === $email) {

            $errors['email'] = "Email already in use.";

        }

    }

    $stmt1->closeCursor();

}

Answer 2

你只是从这个查询中得到计数

$sql = "SELECT uid FROM users WHERE username = :username OR email = :email";

代替

$sql = "SELECT uid,count(uid) FROM users WHERE username = :username OR email = :email";

希望它对单个查询有所帮助