在php中刷新页面后如何避免错误

Question

actually this is regarding a simple query in php i have a simple html login form as follow with post method and login table in the database with fields username password ...etc i am able to get the desire result but when i get the result i refresh that page and an error come 实际上，这是关于php中的简单查询的，我有一个简单的html登录表单，其后是数据库中具有字段用户名密码... etc的post方法和登录表，等等，我能够获得所需的结果，但是当我获得结果时，刷新该页面，出现错误

Notice: Undefined index: usrname in C:\xampp\htdocs\tut\pro\ex1.php on line 9

Notice: Undefined index: password in C:\xampp\htdocs\tut\pro\ex1.php on line 10

.........what i want to know is how can i avoid this error after refreshing the page is there any method to do so. ....我想知道的是刷新页面后如何避免此错误，是否有任何方法可以这样做。

 <html><body>
<form method="post" action="ex1.php">
username:<input type="text" name="usrname" value=""><br>
passsword:<input type="password" name = "password" value=""><br>
<input type="submit" name="submit" value="sign up">
</form>
</html>
</body>

ex1.php is as follow : ex1.php如下：

 <?php
$cxn= mysqli_connect("localhost","root","","movie");
if(mysqli_connect_errno())
{
echo" error connecting ".mysqli_connect_error();
}

if (isset($_POST)) {
$username=$_POST['usrname'];
$password=$_POST['password'];
$sql="select * from login where username= '$username' and password= '$password'";
$result=mysqli_query($cxn,$sql);
unset($_POST);


if($result)
{
if(mysqli_num_rows($result) == '1')
{
echo "<h1>welcome &nbsp".$username."&nbsp on your account</h1>";
}}}
?>

Answer 1

Try changing this, 尝试改变这个，

username:<input type="text" name="usrname"><br>
passsword:<input type="password" name = "password"><br>

$username=$_POST['username'];
$password=$_POST['password'];
$sql="select * from login where username= '$username' and password= '$password'";
$result=mysqli_query($cxn,$sql);

to this.. 对此。

username:<input type="text" name="usrname" value=""><br>
passsword:<input type="password" name = "password" value=""><br>

if (isset($_POST)) {
$username=$_POST['username'];
$password=$_POST['password'];
$sql="select * from login where username= '$username' and password= '$password'";
$result=mysqli_query($cxn,$sql);
unset($_POST);
}

Then your variables will only be created when the user submits the form. 然后，仅当用户提交表单时才创建变量。

在php中刷新页面后如何避免错误

问题描述

1 个解决方案

解决方案1
0 2014-08-02 22:05:05

在php中刷新页面后如何避免错误

问题描述

1 个解决方案

解决方案1 0 2014-08-02 22:05:05

解决方案1
0 2014-08-02 22:05:05