使用 rowCount 从 mysql 返回字段无效

Question

如果电子邮件和密码匹配，我想要以下代码 return 来自 mysql tblUser 的用户 ID。目前它没有 returning 任何东西

<?php

     include 'config.inc.php';

     // Check whether username or password is set from android  
     if(isset($_POST['email']) && isset($_POST['password']))
     {
          // Innitialize Variable
          $result='';
          $email = $_POST['email'];
          $password = $_POST['password'];

          // Query database for row exist or not
          $sql = 'SELECT UserID FROM tblUser WHERE  email = :email AND password = :password';
          $stmt = $conn->prepare($sql);
          $stmt->bindParam(':email', $email, PDO::PARAM_STR);
          $stmt->bindParam(':password', $password, PDO::PARAM_STR);
          $stmt->execute();
          if($stmt->rowCount())
          {
             $result="true" . UserID;   
          }  
          elseif(!$stmt->rowCount())
          {
                $result="false";
          }

          // send result back to android
          echo $result;
    }

?>

Answer 1

For most databases, PDOStatement::rowCount() does not return the number of rows affected by a SELECT statement. Instead, use PDO::query() to issue a SELECT COUNT(*) statement with the same predicates as your intended SELECT statement, then use PDOStatement::fetchColumn() to retrieve the number of rows that will be returned. Your application can then perform the correct action.

相反，您可以

      if($data = $stmt->fetch())
      {
         $result="true".$data['UserID'];
      }  
      else
      {
            $result="false";
      }

使用 rowCount 从 mysql 返回字段无效

Returning a field from mysql using rowCount is not working

php

mysql

pdo

rowcount

bindparam