如何正确哈希登录脚本的密码？

Question

该脚本检查用户尝试登录的用户类型。如果数据正确，则用户将被重定向到该类用户的特殊主页。

脚本：

session_start();
// Making a connection with the database.
$mysqli=new MySQLi("localhost", "user", "password", "dbname"); 
$role=""; 

// Declaring the username and password input.
$username=filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING); 
$password=filter_input(INPUT_POST, 'password', FILTER_SANITIZE_STRING); 

// If role from members where username and password from inputs exicts in database bind parameters.
// If given parameters not excists in database die
if($query=$mysqli->prepare("SELECT `role`, `firstname`, `lastname`, `id` FROM members WHERE username=? AND password=?")) {
    $query->bind_param("ss", $username, $password);                                         
    $query->execute();                                                                
    $query->bind_result($role, $first, $last, $id);
    $query->fetch();
} else {                                                                                    
    echo "Errors in the Query. ".$mysqli->error;                                            
    die();
}

// If $role is filled make session for username to check if logged in and session role for redirect page.
// If $role and $username is not filled invalid password, username combination.
if($role!="") {                                                                           
    $_SESSION['ingelogt'] = $username;                                                        
    $_SESSION['user_role'] = $role; 
    $_SESSION["firstname"] = $first;
    $_SESSION["lastname"] = $last;
    $_SESSION["id"] = $id;                                        
    $location="$role.php";                                                                  
    header("location: $location");                                                          
} else {                                                                                   
    echo "Invalid password, username combination";
    echo "<br/><a href='loginHTML.html'>Click to go back</a>";                                          
}

现在我想知道如何对密码进行散列是一种好方法，因为只是常规的密码输入是不安全的。如果您在此脚本中看到任何其他改进，请随时告诉我，我只是一个初学者。