Requesting Username & Password In PHP Session - php

Question

i tried to put username & password dynamically but
It doesnt work with stored username & password in DB and stays on same page....
really depressed.
<?php include "../db/db_connection.php";
$username = $_POST['txt_username'];
$pwd =$_POST["txt_pwd"];
if(empty($username) || $username == ""){
header("location:index.php?err_msg=1");
exit;
}
if(empty($pwd) || $pwd == ""){
header("location:index.php?err_msg=2");
exit;
}
$sql = "SELECT username,password FROM users WHERE username= '$username' and password= '$pwd'";
$result = mysqli_query($con,$sql);
if(mysqli_num_rows($result)==1){
header("location:dashboard.php");
}
else{
header("location:index.php?err_msg=3");
}
if($_REQUEST['txt_username'] == $username && $_REQUEST['txt_pwd'] == $pwd){
$_SESSION['txt_username'];
$_SESSION['txt_pwd'];
header("Location:dashboard.php");
}
else{
header("Location:index.php");
}
?>`

Answer 1

Those lines doesn't nothing..
$_SESSION['txt_username'];
$_SESSION['txt_pwd'];
maybe:
$_SESSION['txt_username'] = $user;
$_SESSION['txt_pwd'] = ...;
?

Answer 2

You can try this, I am not sure if this is exactly what you are looking for...
<?php session_start();
$username = $_POST['txt_username'];
$pwd =$_POST["txt_pwd"];
if(empty($username) || $username == ""){
header("location:index.php?err_msg=1");
exit;
}
if(empty($pwd) || $pwd == ""){
header("location:index.php?err_msg=2");
exit;
}
$sql = "SELECT username,password FROM users WHERE username= '$username' and password= '$pwd'";
$result = mysqli_query($con,$sql);
if(mysqli_num_rows($result)==1){
$_SESSION['txt_username'] = $username;
$_SESSION['txt_pwd'] = $pwd;
header("location:dashboard.php");
}
else{
header("location:index.php?err_msg=3");
}
header("Location:index.php"); // if it stays on the same page remove this line
?>

Answer 3

I restructured your code to look more clean.
Also I suggest you to avoid using mysql and start using mysqli (or PDO) to avoid SQL injection attacks.
<?php session_start();
if(isset($_SESSION['txt_username']) && !empty($_SESSION['txt_username'])) {
//If we enter here the user has already logged in
header("Location:dashboard.php");
exit;
}
if(!isset($_POST['txt_username'])) {
header("location:index.php?err_msg=1");
exit;
}
else if(!isset($_POST["txt_pwd"])) {
header("location:index.php?err_msg=2");
exit;
}
$username = $_POST['txt_username'];
$pwd = $_POST["txt_pwd"];
//We use MYSQL with prepared statements BECAUSE MYSQL IS DEPRECATED
$mysqli = new mysqli('localhost', 'my_bd_user', 'mi_bd_password', 'my_bd');
$sql = "SELECT 1 FROM users WHERE username= ? and password = ?";
$stmt = $mysql->prepare($sql);
$stmt->bind_param("ss", $username, $password);
$stmt->execute();
$stmt->bind_result($result);
$stmt->fetch();
if(!empty($result)) {
//IF we enter here user exists with that username and password
$_SESSION['txt_username'] = $username;
header("location:dashboard.php");
exit;
}
else{
header("location:index.php?err_msg=3");
}
Try it.

Answer 4

I checked your code and found everything is correct .I wold like you to add connection file on this.
Like
$username = "root";
$password = "password";//your db password
$hostname = "localhost";
//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password)
or die("Unable to connect to MySQL");
//select a database to work with
$selected = mysql_select_db("db name",$dbhandle)
or die("Could not select Database");
Thanks

Answer 5

Try below code :
i have reviewed and changed your code :
<?php session_start();
mysqli_connect("locahost","username","password");
mysqli_select_db("database_name");
$username = trim($_POST['txt_username']);
$pwd = trim($_POST["txt_pwd"]);
if($username == ''){
header("location:index.php?err_msg=1");
exit;
}
if($pwd == ""){
header("location:index.php?err_msg=2");
exit;
}
$sql = "SELECT `username`,`password` FROM users WHERE `username`= '".$username."' and password= '".$pwd."'";
$result = mysqli_query($sql);
if(mysqli_num_rows($result)>0){
$_SESSION['txt_username'] = $username;
$_SESSION['txt_pwd'] = $pwd;
header("location:dashboard.php");
}
else{
header("location:index.php?err_msg=3");
}
?>