MySQLi stmt num_rows returning 0

本文关键字：returning rows stmt num MySQLi | 更新日期: 2023-09-27

我在PHP中使用$stmt->num_rows时遇到问题，我不确定我做错了什么。$stmt->num_rows在本应返回1的情况下返回0。查询执行，并在phpMyAdmin中执行时返回1个结果。如有任何帮助，我们将不胜感激。

public function get_login($username, $password)
{
    $query = "SELECT `id` FROM `users` WHERE `username` = ? AND `password` = ? LIMIT 1;";
    if($stmt = $this->prepare($query))
    {
        $stmt->bind_param('ss', $username, $password);
        if($stmt->execute())
        {
            $stmt->bind_result($id);
            $stmt->fetch();
            $stmt->store_result();
            if($stmt->num_rows > 0)
            {
                return $id;
            }
            return false;
        }
        return false;
    }
    return false;
}

试试这个，先调用store_result，然后调用fetch作为结果。

public function get_login($username, $password)
{
    $query = "SELECT `id` FROM `users` WHERE `username` = ? AND `password` = ? LIMIT 1;";
    if($stmt = $this->prepare($query))
    {
        $stmt->bind_param('ss', $username, $password);
        if($stmt->execute())
        {
            $stmt->bind_result($id);
            $stmt->store_result();
            $stmt->fetch();          
            if($stmt->num_rows > 0)
            {
                return $id;
            }
            return false;
        }
        return false;
    }
    return false;
}