使用PHP中的password_verify（）使用Mysql中存储的哈希密码对登录进行身份验证

Question

我有一个网站，正在使用password_hash()和password_verify()对注册/登录系统进行编程。 我已将带有哈希密码的注册详细信息成功插入数据库中。 我的问题是如何使用此哈希密码对用户进行身份验证。

以下是验证码：

<?php
session_start();
$host="localhost";
$username="yyy";
$password="yyyy";
$db_name="yyyy";
$tbl_name="users";
$link = new mysqli("$host", "$username", "$password", "$db_name");
if (mysqli_connect_error()) {
die('Connect Error (' . mysqli_connect_errno() . ') '
        . mysqli_connect_error());
}
$username = mysqli_real_escape_string($link, $_POST['username']);
$pwd = mysqli_real_escape_string($link, ($_POST['password']));
$query = mysqli_query($link, "SELECT * from $tbl_name WHERE username='$username'"); //Query the     users table if there are matching rows equal to $username
$exists = mysqli_num_rows($query); //Checks if username exists
$table_users = "";
$table_password = "";
$password = 0 ;
if($exists > 0) //IF there are no returning rows or no existing username
{
    while($row = mysqli_fetch_assoc($query)) //display all rows from query
    {
        $table_users = $row['username']; // the first username row is passed on to $table_users, and so on until the query is finished
        $table_password = $row['password']; // the first password row is passed on to $table_users, and so on until the query is finished
$password = (password_verify($pwd, $table_password));

    }

    if(($username == $table_users) && ($password)) 
    {
        if($password) {

                $_SESSION['user'] = $username; //set the username in a session. This serves as a global variable
                header("location: session.php"); // redirects the user to the authenticated home page
        }

    }
    else
    {
        Print '<script>alert("Incorrect Password!");</script>'; 
        Print '<script>window.location.assign("login.php");</script>'; 
    }

}
else
{
    Print '<script>alert("Incorrect Username!");</script>'; 
    Print '<script>window.location.assign("login.php");</script>'; 
}
?>

password_verify()似乎总是向$password变量返回false或0“。感谢您的帮助。