Coding Corner: HTML , PHP

In this post i will show you how to create a basic login page and check those values in the database and also do some error checking like empty values are not allowed.

Here i will use xampp as a server and it has a database with 4 columns username , password, gender and name. (refer to my previous post on creating a registration form)

Now open a file in any text editor and place the following code :

<!DOCTYPE HTML> 
<html>
   <head></head>
   <body>
      <?php
         $servername = "127.0.0.1";
         $username = "codingcorner";
         $password = "yourPassword";
         $dbname="sample";
         
         
          $StatusValid = $StatusInValid =$unameErr  = $pwdErr = " ";
          $uname  = $pwd = "";
         
         if ($_SERVER["REQUEST_METHOD"] == "POST") {
           
         
           if (empty($_POST["uname"])) {
             $unameErr = "Username is required";
           } else {
             $uname = test_input($_POST["uname"]);
           }
         
           if (empty($_POST["pwd"])) {
             $pwdErr= "Password is required";
           } else {
             $pwd = test_input($_POST["pwd"]);
           }
         
           
         }
         ?>
      <h2>A Simple Login Form</h2>
      <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> 
         Username: <input type="text" name="uname">
         <span class="error">* <?php echo $unameErr;?></span>
         <br><br>
         Password: <input type="password" name="pwd">
         <span class="error">*<?php echo $pwdErr;?></span>
         <br><br>
         <input type="submit" name="submit" value="Login"> 
      </form>
      <br><br>
      <?php
         $conn = mysqli_connect($servername, $username, $password,$dbname);
         
         if (!$conn) {
         die("Connection failed: " . mysqli_connect_error());
         }
         $sql= ("SELECT username, password FROM users WHERE username='$uname' && password='$pwd'");
         $result = mysqli_query($conn, $sql);
         if ($result && mysqli_num_rows($result) >0)
         {
             $StatusValid = "Successfully Logged in"; 
         }
         else
         {
         $StatusInValid = 'Username and Password NOT Found , TRY AGAIN !!';
         }
         mysqli_close($conn);
         
         function test_input($data) {
         $data = trim($data);
         $data = stripslashes($data);
         $data = htmlspecialchars($data);
         return $data;
         }
         
         echo "STATUS :";
         if ($_SERVER["REQUEST_METHOD"] == "POST") {
         echo $StatusValid; 
         echo $StatusInValid; 
         }
         ?>
   </body>
</html>

OUTPUT :

Initially