mysql problem using php when update table - php

This system is based on invitation codes, if u have a code that is present in the database you can submit the input therefore change a value in a row. There are 2 inputs, 1) Invitation Code (key), if exist in the database the user can submit the value 2)Name (user). I done the following code but it doesn't work, any suggestions?
<?php
//get value pass from form in login.php
$username = $POST['user'];
$password = $POST['key'];
//connect to the server and select database
mysql_connect("localhost", "...","...");
mysql_select_db("...");
// Query the database for user
$result = mysql_query("UPDATE invitation_keys SET name ='$username' WHERE key = '$password'";)
or die("Failed to query database".mysql_error());
$row = mysql_fetch_array($result);
if ($row['key'] == $password) {
echo "Login success!!!".$row['key'];
} else {
echo "Failed to login";
}
?>

When you are coding in PHP, var_dump($var) is your best friend.
So the first thing to do here, is to print the query.
You will see, that your $username and $password vars are NULL, because you missed the syntax of $_POST[].
After, you can put in var_dump what you want, and that's why its interesting, because you will debug faster with this.

Related

How to make php to redirect each user to their own respective pages?

ok, so i have a little issue here with php. I know there are alot of similar questions, but ones i found did not help.
I dont want to use anything more like javascript or something. I got mysql set up, there are 3 columns ID username and password.
<?php
$username = $_POST['user'];
$password = $_POST['pass'];
$username = stripcslashes($username);
$password = stripcslashes($password);
$username = mysql_real_escape_string($username);
$password = mysql_real_escape_string($password);
mysql_connect("localhost","root","");
mysql_select_db("login");
$result = mysql_query("select * from users where username='$username' and password= '$password'")
or die("failed to query DB".mysql_error());
$row = mysql_fetch_array($result);
if ($row['username'] == $username && $row['password'] == $password) {header(suc.html);
die();}else{header("Location: fail.html");die();}
?>
This code, it works but when i dont fill in any details and press submit too, it gets me to the suc.html which shows successful login. Now i want to make the following:
I'll make ID's similar to each individual html's names, then the php will go match the ID number with the file name in the directory, and show the page for the respective user.
like lets say user1.
Login userlol password 123 ID user1 file user1.html
then what code to use that it goes and matches the ID user1 with the .html name, then redirects the user to their own custom page. Is there a way? Kinda getting started with php ,so cut some slack please :)
p.s i know these codes are older php codes, but anything works for me personally.
You are getting that sort of behaviour because when a username and password is not submitted, their respective values evaluates to null and your SQL query is successful but returns 0 rows thereby making your $row['username'] and $row['password'] to be null. In general, your $row['username'],$row['password'],$username,$password would all be equal to null which fulfills all the requirements to redirect to "suc.html"
To solve this problem, simply check if mysql_num_rows($result)==1 because usually, a successful login would return just one row due to unique usernames.
But
I would not advice you to continue with deprecated mysql and SQL Injection susceptible logic. Please allow me to rewrite your logic as follows:
<?php
$username = $_POST['user'];
$password = $_POST['pass'];
// You don't have to escape or sanitize user inputs if you use Prepared Statement plus sanitizing user password is highly discouraged.
// $username = stripcslashes($username);
// $password = stripcslashes($password);
// $username = mysql_real_escape_string($username);
// $password = mysql_real_escape_string($password);
// Initiate a PDO connection and set your error mode to exception.
$conn=new pdo("mysql:host=localhost;dbname=login;","root","",array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
try{
// Prepare your query and replace all values with ? which would be provided as an array in execute(); I added limit 1 to make sure we are getting a maximum of one row from our query.
$result_stmt = $conn->prepare("select * from `users` where (`username`=? and `password`=?) limit 1");
$result_stmt->execute([$username,$password]);
// fatch() would return a single row just like mysql_fetch_array or mysql_fetch_assoc while fetchAll() would return all rows.
$result=$result_stmt->fetch();
if(count($result)==1){
// There is no need to check this again because your query to the database already did.
// if ($row['username'] == $username && $row['password'] == $password)
// Redirect users to the same page but identify each user through session (recommended)
header("location:suc.html");
}else{
header("location:fail.html");
}
}catch(Exception $e){
echo $e->getMessage();
}
?>

How to echo an item from a database

I am still in the process of learning PHP so forgive me for the poor code.
I am attempting to get the users first name to output once they have logged in, however nothing is returning, please may I have some help.
<?php
session_start();
$DATABASE_HOST="localhost";
$DATABASE_USER="root";
$DATABASE_PWORD="";
$DATABASE_NAME="registration";
$connection=mysqli_connect($DATABASE_HOST, $DATABASE_USER, $DATABASE_PWORD, $DATABASE_NAME);
if (mysqli_connect_errno()){
//if there is an issue with connecting to the database, ends code and displays the error
die("failed to connect to server: " .mysqli_connect_error()); //kills program
}
if (!isset($_POST['email'], $_POST['pswd'])){ //checking if both fields were inputted into on the form, isset()checks if data exists
//unable to get data
die("please fill in both email and password"); //kills program
}
$email = mysqli_real_escape_string($connection, $_POST['email']); //saves input as string, preventing misinterpretation
$password = mysqli_real_escape_string($connection, $_POST['pswd']);//saves input as string, preventing misinterpretation
$SQLstatement = "SELECT * FROM users WHERE email='$email' and password='$password'"; //querys the database for match
$Queryresult = mysqli_query($connection, $SQLstatement) or die(mysqli_error($connection)); //runs the query
$rowsQueryResult = mysqli_num_rows($Queryresult);//number of 'emails' in database where the emails match
$dbFirstName=$rowsQueryResult ['firstName'];
if ($rowsQueryResult==1){//if the number of emails where a match is made, is 1
echo "Welcome $dbFirstName <br/> ";
echo "successful login. <a href='accountPage.php'>Click</a> here to access the accounts page"; //successful login, links to accounts page
$_SESSION['firstName']=$dbFirstName;
}else{ //if matches are 0 or >=2
die ('unsuccessful login'); //kills program
}
?>
Thank you for your time and help
This problem can be solved by using the mysqli_fetch_assoc() function in place of mysqli_num_rows(). However, I would recommend you to use PDO since it's easier to implement and more readable.
The mysqli_num_rows() function returns the number of rows in a result set.
$rowsQueryResult = mysqli_num_rows($Queryresult);`
will give number of 'emails' in database where the emails match.
You need to use mysqli_fetch_assoc() as
$row = mysqli_fetch_assoc($Queryresult);
$dbFirstName=$row['firstName'];

How do I double check my PHP signin form

I made a signin form that will look through the database and find a match to the user's credentials, but how do I fix this code so it will relocate the page if there is no match.
<?php
session_start();
include_once 'includes/dbh.php';
$username = $_POST['u_name'];
$password = $_POST['pwd'];
$sql = "SELECT * FROM users;";
$result = mysqli_query($conn, $sql);
while ($row = mysqli_fetch_assoc($result)) {
if ($username == $row['username'] && $password == $row['password']) {
$_SESSION['username'] = $username;
header("Location: second_index.php?signinSuccessful");
}
if ($username != $row['username'] && $password != $row['password']) {
header("Location: index.php?NotSucessful");
}
}
I tried putting the code inside of the loop, but I know that can't work, and if I put it outside of the loop, It redirects even if the credentials are correct. Please help. Thanks
First of all, this is totally wrong, you're looping trough all the users to see if the user exist, instead of that sql statement try $sql = "SELECT * FROM users where user='$user' and password='$password'";
And to avoid any data breach in that sql statemen you have to serialize the user and pass like that before adding it to the statement
$user = mysql_real_escape_string($conn, $user);
$password =mysql_real_escape_string($conn, $password);
Then you only check if the fields aren't empty (which means the user exist)
You are getting all the users from the users table and checking each record manually in php.
The reason why your code doesn't work is because the while loop doesn't check all the users in user table. If the first record in the retrieved table data doesn't match with entered username and password, it will go to 2nd if block and redirect.
You should change your query to filter by user-entered values.
SELECT * FROM USERS WHERE USERNAME = 'username' AND PASSWORD='password'
And later check in php if any record is returned. If any record is returned, it is a valid user, else redirect the user to failed authentication page.
As a good practice, make sure to use parameterized query.
Update Replace the while loop and block with this.
if(mysqli_num_rows($result) > 0){
// valid user
}else{
// invalid user
}
Why do you need while loop in this case when you fetching data from database? Using sql and make the database fetch the only one correct answer, don't make server site do unnecessary work.
I propose just do simple fetch then if check, no need for while loop at all.
Your logic is always redirect to index.php when username password not correct so of course it will always do so when your while loop on server do not hit the correct user.

PHP login script using bind_result in subsequent query mysqli

I'm trying to build a relatively simple PHP login script to connect to MySQL database running on my home server. I know the connection works as I've gotten some data returned as I would expect. However, I am having trouble getting the full script to work.
Essentially, I'm taking in a username/password from the user, and I first do a lookup to get the user_id from the users table. I then want to use that user_id value to do a comparison from user_pswd table (i'm storing usernames and passwords in separate database tables). At one point, I was able to echo the correct user_id based on the username input. But I haven't been able to get all the issues worked out, as I'm pretty new to PHP and don't really know where to see errors since I load this onto my server from a remote desktop. Can anyone offer some advice/corrections to my code?
The end result is I want to send the user to another page, but the echo "test" is just to see if I can get this much working. Thanks so much for the help!
<?php
ob_start();
$con = new mysqli("localhost","username","password","database");
// check connection
if (mysqli_connect_errno()) {
trigger_error('Database connection failed: ' . $con->connect_error, E_USER_ERROR);
}
$users_name = $_POST['user'];
$users_pass = $_POST['pass'];
$user_esc = $con->real_escape_string($users_name);
$pass_esc = $con->real_escape_string($users_pass);
$query1 = "SELECT user_id FROM users WHERE username = ?;";
if ($result1 = $con->prepare($query1)) {
$result1->bind_param("s",$user_esc);
$result1->execute();
$result1->bind_result($userid);
$result1->fetch();
$query2 = "SELECT user_pswd_id FROM user_pswd WHERE active = 1 AND user_id = ? AND user_pswd = ?;";
if ($result2 = $con->prepare($query2)) {
$result2->bind_param("is",$userid,$pass_esc);
$result2->execute();
$result2->bind_result($userpswd);
$result2->fetch();
echo "test", $userpswd;
$result2->free_result();
$result2->close();
} else {
echo "failed password";
}
$result1->free_result();
$result1->close();
}
$con->close();
ob_end_clean();
?>

How do I update a query according to Email of the user?

I am trying to add a username field in my profile page. First of all, to access that profile page, the user must log in. And is identified through a unique value in this case, his email. Now back to the username field. Currently, my username query inserts whatever username I enter, to the id 1 of the MySQL database. I want it to update according to the email of the user. This way it'll be inserted to the correct row.
It's current working is as following:
As you can see, I'm inputting the username from a different e-mail: http://imgur.com/BQsZz8Q
But it still updates in the ID 1: http://imgur.com/mVgyMik
This is my action.php:
<?php
session_start(); //---> start session
ini_set('display_errors', 1); ini_set('log_errors',1); error_reporting(E_ALL); mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$con = mysqli_connect('localhost', 'id1753243_venom', 'roushan123', 'id1753243_gameware_01');
if(!$con)
{
echo 'Not connected to the server';
}
if(isset($_POST['username']))
{
$username = $_POST['username'];
$sql = "UPDATE users SET username='".mysqli_real_escape_string($con,$username)."' WHERE id = 1";
$insert = mysqli_query($con,$sql);
$_SESSION['username'] = $username; //---> this will store username into session variable
}
if(!$insert)
{
echo 'Not inserted';
}
else
{
echo 'Inserted';
}
header("refresh:2; url=user.php");
?>
I'm a beginner but I do know the problem is in the WHERE clause. What I don't know is, how to change the code to my needs i.e update the query and store username according to the email of the user logged in.. I'm hoping one of you can help me in this case! Thanks a lot!
PS: I know the PHP code is not secure, this is just a test.
Query is correct but you have made a little mistake of email parameter in query. There should be a email parameter in posted data and email column in table then change the query by altering the where condition as mentioned below:
WHERE id = 1 to email=$_POST['e-mail']

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