Question

我需要帮助检查用户名是否已经注册或存在于表中。我尝试了很多，但它似乎只是让它成真。

我的代码是：

//=============Configuring Server and Database=======
$host        =    'localhost';
$user        =    'root';
$password    =    '';
//=============Data Base Information=================
$database    =    'login';

$conn        =    mysql_connect($host,$user,$password) or die('Server Information is not               Correct'); //Establish Connection with Server
mysql_select_db($database,$conn) or die('Database Information is not correct');

//===============End Server Configuration============

//=============Starting Registration Script==========

$username    =    mysql_real_escape_string($_POST['username']);

$password    =    mysql_real_escape_string($_POST['password']);

$email    =    mysql_real_escape_string($_POST['email']);

$country    =    mysql_real_escape_string($_POST['country']);



if(isset($_POST['btnRegister'])) //===When I will Set the Button to 1 or Press Button to  register
{
$query    =    "insert into     users(username,password,email,country)values('$username','$password','$email','$country')" or    die ('username allready exist');
$res    =    mysql_query($query);
header("location:load.php");

Answer 1

替换：

$query    =    "insert into     users(username,password,email,country)values('$username','$password','$email','$country')" or    die ('username allready exist');
$res    =    mysql_query($query);

使用：

$query    =    "insert into     users(username,password,email,country)values('$username','$password','$email','$country')" ;
$res    =    mysql_query($query) or    die ('username allready exist');

原始代码的问题在于您正在检查$ query变量是否已正确实例化（我没有理由不这样做）。您需要检查查询是否成功执行，即检查查询调用的结果（在您的情况下为mysql_query）。

请注意，您的生产代码不应使用mysql_ *函数（这不是一种好的做法），而应使用预处理语句。见这里：[http://uk1.php.net/manual/en/function.mysql-query.php][1]

Please, don't use mysql_* functions in new code。它们不再被维护and are officially deprecated。请参阅red box？转而了解prepared statements，并使用PDO或MySQLi - this article将帮助您确定哪个。如果您选择PDO here is a good tutorial。

检查用户名是否已注册到表

1 个答案: