How to validate input from database - php

i develop captcha that require the user to answer a question that randomly display. My database consist of id,question,answer. The problem is although i enter correct answer it still redirected me to error.php instead of success.php.
<?php
$database_db="test2";
$user_db="root";
$password_db="";
$host_db="localhost";
$link = mysqli_connect($host_db, $user_db, $password_db, $database_db);
/* check connection */
if (mysqli_connect_errno())
{
die ("couldnot connect: ".mysqli_connect_error());
exit();
}
if (array_key_exists("answer", $_POST) AND array_key_exists("question", $_POST))
{
$id = intval($_POST['question']);
$sql="SELECT question, answer FROM captcha WHERE question='$id' AND answer='".mysqli_real_escape_string($link, $_POST['answer'])."'";
$result = mysqli_query($link, $sql) or exit('$sql failed: '.mysqli_error($link));
$num_rows = mysqli_num_rows($result);
if($num_rows > 0)
{
header("Location: success.php");
}
else
{
header("Location: error.php");
}
exit;
}
else
{
$query = "SELECT id, question FROM `captcha` ORDER BY RAND() LIMIT 1";
if ($result = mysqli_query($link, $query))
{
if ($row = mysqli_fetch_assoc($result))
{
$id = $row["id"];
$question = $row["question"];
}
}
}
?>
<html>
<body>
<form method="post">
<?php echo $question; ?><br />
<input type="hidden" name="question" id="question" value="<?php echo $id; ?>" />
<input type="text" name="answer" id="answer" /><br />
<input type="submit" name="submit" value="submit" /><br />
</form>
</body>
</html>

It looks like you're querying the wrong column for a match to $id:
"SELECT question, answer FROM captcha WHERE question='$id' AND ... "
I think this should be:
"SELECT question, answer FROM captcha WHERE id='$id' AND ... "

Related

How to edit/update data in mysql using php

I've been researching everywhere regarding this matters and i still cant edit/update my entry. Noted, this is my first real program and my level is somewhat mediocre. So i would like to seek your advise/help regarding this matter.
CODE:
<?php
include('config.php');
if(isset($_POST['edit']))
{
$sql = "select * from hotels where BIL =" .$_GET['edit'];
$result = mysqli_query($link, $sql);
$row = mysqli_fetch_array($result);
}
if(isset($_POST['submit'])){
$hotel = $_POST['hotel'];
$address = $_POST['address'];
$update = "update hotels set $hotel = 'hotel', $address = 'address' where BIL = ".$_GET['edit'];
$up = mysqli_query($link, $update);
if (isset($sql)){
die ("Error $sql" .mysqli_connect_error());
}
else
{
header ("location: view.php");
}
}
?>
<html>
<body>
<form method="post" >
New Hotel: <br />
<textarea name="hotel" cols="50" rows="2" value="<?php echo $row['hotel']; ?>" /></textarea>
<br />
Address: <br / >
<textarea name="address" cols="50" rows="10" value="<?php echo $row['address']; ?>" /></textarea><br /><br />
<input type="submit" name="submit" value="update" />
</form>
<script>
function update(){
var x;
if(confirm("update Succesfully") == true){
x= "update";
}
}
</script>
</body>
</html>
Extra note: I copied this code from a youtube channel...
https://www.youtube.com/watch?v=jQzRDwY6zPc
Thanks in advance!

HTML form not passing values to PHP (mysqli_real_escape_string)

HTML
<form type="POST" action="includes/login.php">
<input type="email" name="email" placeholder="email" />
<input type="password" name="password" placeholder="parola" />
<input type="submit" value="Login">
</form>
PHP
<?php
require_once 'config.php';
if(isset($_POST['email']))
{
$email = mysqli_real_escape_string($_POST['email']);
}
else
{
echo "Nu ati completat adresa de e-mail. <br />";
}
if(isset($_POST['password']))
{
$email = mysqli_real_escape_string($_POST['password']);
}
else
{
echo "Nu ati completat parola. <br />";
}
if(isset($_POST['email']) && ($_POST['password']))
{
$query = ("SELECT * FROM `users` WHERE password = '$password' AND email = '$email'");
$result = mysqli_query($link, $query);
$row = mysqli_fetch_array($result);
$count_rows = mysqli_num_rows($result);
if ($count_rows == 1)
{
$_SESSION["login"] = "OK";
header("Location: ../index.php");
}
else
{
header("Location: ../login.php");
}
}
?>
I tried switching from MySQL to MySQLi and I'm sure it's related to this. My form is not passing values to the PHP script even if the inputs have a name. Did some research here on StackOverflow and found many questions about forms not passing data but there was usually a typo or a missing name, which is not my case (I think).
(I know that the password is not secured yet, I'll add a SHA256 or something there soon so don't stress about it)
Tried echoing the query and it's just blank where the password and email address should be.
SELECT * FROM `users` WHERE password = '' AND email = ''
I also get this warning:
Warning: mysqli_real_escape_string() expects exactly 2 parameters, 1 given in C:\xampp\htdocs\breloc\includes\login.php on line 4
Line 4 in my script is:
$email = mysqli_real_escape_string($_POST['password']);
make change to Your form tag
<form type="POST">
to
<form method="POST">
Change form type="post" to method="post"
Add database connection string to your mysqli_real_escape_string function.
According to the Documentation http://php.net/manual/de/mysqli.real-escape-string.php
you must provide the mysqli ressource as first parameter of the function.
You should use method instead of type in your <form> tag, like this:
<form method="POST" action="includes/login.php">
<form method="POST" action="includes/login.php">
<input type="email" name="email" placeholder="email" />
<input type="password" name="password" placeholder="parola" />
<input type="submit" value="Login" name="submit">
</form>
<?php
require_once 'config.php';
if(isset($_POST['submit'])) {
if(!empty($_POST[email]))
{
$email = mysqli_real_escape_string($link,$_POST['email']);
}
else
{
echo "Nu ati completat adresa de e-mail. <br />";
}
if(!empty($_POST['password']))
{
$password = mysqli_real_escape_string($link,$_POST['password']);
}
else
{
echo "Nu ati completat parola. <br />";
}
if(!empty($_POST['email']) && !empty($_POST['password']))
{
$query = ("SELECT * FROM `users` WHERE password = '".$password."' AND email = '".$email."'");
$result = mysqli_query($link, $query);
$row = mysqli_fetch_array($result);
$count_rows = mysqli_num_rows($result);
if ($count_rows == 1)
{
$_SESSION['login'] = "OK";
header("Location: ../index.php");
}
else
{
header("Location: ../login.php");
}
}}
?>
set 'method' not type
<form method="POST" action="includes/login.php">
<input type="email" name="email" placeholder="email" />
<input type="password" name="password" placeholder="parola" />
<input type="submit" value="Login">
</form>
don't forget to connect to your db and pass the that connection to your mysqli_query and mysqli_real_escape_string functions
<?php
require_once 'config.php';
$con=mysqli_connect("localhost","my_user","my_password","my_db");
if(isset($_POST['email']))
{
$email = mysqli_real_escape_string($con, $_POST['email']);
}
else
{
echo "Nu ati completat adresa de e-mail. <br />";
}
if(isset($_POST['password']))
{
$email = mysqli_real_escape_string($con,$_POST['password']);
}
else
{
echo "Nu ati completat parola. <br />";
}
if(isset($_POST['email']) && ($_POST['password']))
{
$query = ("SELECT * FROM `users` WHERE password = '$password' AND email = '$email'");
$result = mysqli_query($con, $query);
$row = mysqli_fetch_array($result);
$count_rows = mysqli_num_rows($result);
if ($count_rows == 1)
{
$_SESSION["login"] = "OK";
header("Location: ../index.php");
}
else
{
header("Location: ../login.php");
}
}
?>
string mysqli_real_escape_string ( mysqli $link , string $escapestr )
As from Docs, the first parameter must be mysqli resource and its missing within your code, and also change
<form type="POST">
into
<form method="post">
So your code looks like
mysqli_real_escape_string($link,$_POST['email']);// and been repeated at all those occurences

How to edit table values in MySQL and PHP?

I have that people can add team names to my MySQL table. Now I want them to edit it. I have tried several tutorials but i can't figure it out. I like to know what i am doing wrong.
This is my admin.php:
<?php
$username = "root";
$password = "";
$hostname = "localhost";
$dbhandle = mysql_connect($hostname, $username, $password) or die("Could not connect to database");
$selected = mysql_select_db("login", $dbhandle);
if(isset($_POST['team'])){
$team = $_POST['team'];
$ID = $_POST['id'];
$query = mysql_query("SELECT * FROM e2teams WHERE Team='$team' and ID='$ID'");
if(mysql_num_rows($query) > 0 ) { //check if there is already an entry for that username
echo "$team bestaat al!";
}
else{
mysql_query("INSERT INTO e2teams (Team) VALUES ('$team')");
header("location:e2admin.php");
}
}
mysql_close();
?>
<html>
<body>
<h1>Add teams</h1>
<form action="e2admin.php" method="POST">
<input type="text" name="team" placeholder="Team naam" /><br>
<input type="submit" value="Toevoegen" />
</form>
<?php
$table = "e2teams";
$sql = "SELECT * FROM e2teams";
$result = mysql_query($sql, $dbhandle);
if(mysql_num_rows($result) > 0){
while($row = mysql_fetch_array($result)) {
echo $row['Team']. "<a href='edit.php?edit=$row[1]'>Bewerk</a><br>";
}
}
?>
</body>
</html>
The add teams works. but the edit button doesn't work yet. If I click on edit I go to the edit.php page; here I want to add the new name and need the Team to change in the MySQL row.
This is my edit.php:
<?php
$username = "root";
$password = "";
$hostname = "localhost";
$dbhandle = mysql_connect($hostname, $username, $password) or die("Could not connect to database");
$selected = mysql_select_db("login", $dbhandle);
if( isset($_GET['edit'])) {
$id = $_GET['edit'];
$res = mysql_query("SELECT * FROM e2teams");
$row= mysql_fetch_array($res);
}
if (isset ($_POST['nieuwenaam'])) {
$newname = $_POST['nieuwenaam'];
$id = $_POST['id'];
$sql = "UPDATE e2teams SET Team='$newname' WHERE id='$id'";
$res = mysql_query($sql) or die ("Fout bij updaten".mysql_error());
echo "<meta http-equiv='refresh' content='0;url=edit.php'>";
}
?>
<html>
<body>
<form action="edit.php" method="POST">
<input type="text" name="nieuwenaam" placeholer="test" /><br>
<input type="hidden" name="id" placeholder="idnaam" value"s" /><br>
<input type="submit" value="Update" />
</form>
</body>
</html>
I also like to know how to delete team names but this is maybe for a next question.
This should work:
<?php
$username = "root";
$password = "";
$hostname = "localhost";
$dbhandle = mysql_connect($hostname, $username, $password) or die("Could not connect to database");
$selected = mysql_select_db("login", $dbhandle);
$id = intval($_GET['edit']);
if($id > 0) {
$res = mysql_query("SELECT * FROM e2teams WHERE `id` = $id");
$row= mysql_fetch_array($res);
$newname = mysql_real_escape_string($_POST['nieuwenaam']);
if (!empty($newname)) {
$sql = "UPDATE e2teams SET Team='$newname' WHERE id=$id";
$res = mysql_query($sql) or die ("Fout bij updaten".mysql_error());
echo "<meta http-equiv='refresh' content='0;url=edit.php?edit=$id'>";
}
}
?>
<form action="edit.php?edit=<?= $id; ?>" method="POST">
<input type="text" name="nieuwenaam" placeholer="test" /><br>
<input type="submit" value="Update" />
</form>
</body>
</html>
Edit: Also, about the intval() and mysql_real_escape_string(). Since you were using $_GET without any filter, I've added intval() function on it. Without filtering $id you could've been easily attacked by some sort of e.g. SQL Injection. Same with mysql_real_escape_string(). You might read about this filter function in php manual. For further study I recommend changing mysql_ functions to PDO or mysqli prepared statements. Happy coding!
Check your edit form. You have to put the value attribute like this value="s" no like value"". I think thats all.
I assume when they click on the edit link it's passing the id of the team so the edit.php select should be something like:
$id = (int)$_GET['edit'];
if (!empty($id))
{
$sql = "SELECT * FROM e2teams WHERE id='$id'";
$result = mysqli_query($sql);
$row = mysql_fetch_assoc($res);
}
//... keep the rest of code as is
Now you need to change the HTML form to:
<form action="edit.php?edit=<?php echo $row['id'] ?>" method="POST">
<input type="text" name="nieuwenaam" placeholer="test" value="<?php echo $row['Team'] ?>" /><br>
<input type="hidden" name="id" placeholder="idnaam" value"<?php echo $row['id'] ?>" /><br>
<input type="submit" value="Update" />
</form>

PHP webpage has a direct loop error?

I have been trying to create a login page in PHP to no avail though, i have been getting a "This webpage has a redirect loop" error when i try to run it, so i was wondering if anyone could possibly spot my mistakes? Here is my code:
<?php
require_once("nocache.php");
$id = $_POST["id"];
$pword = $_POST["pword"];
if (!empty($_POST){
if (!empty($id) || !empty($pword)){
require_once("dbconn.php");
$sql = "select username, school_type from school_info where username = '$id' and password = '$pword'";
$rs = mysql_query($sql, $dbConn);
if (mysql_num_rows($rs)> 0 ) {
session_start();
$_SESSION["who"] = $id;
$_SESSION["school_type"] = mysql_result($rs,0,"school_type");
header("location: EOI_home.php");
}
}
else {
header("location: login.php");}
} else {
header("location: login.php");}
?>
<form method="POST" action="<?php echo $_SERVER["PHP_SELF"];?>" id="login">
ID: <input type="text" name="id" /><br/>
pword: <input type="password" name="pword" /><br/>
<input type="submit" value="log in" />
<input type="reset" />
</form>
All of the answers given are technically correct, the way you've set your logic is incorrect... take the following example and port it across into your own code.
<?php
$id = $_POST["id"];
$pword = $_POST["pword"];
if(!empty($_POST)) {
// The form was submitted, perform validation here.
if(!empty($id) || !empty($pword)) {
// Form validation passed, insert into database
} else {
// Form validation failed, display an error or redirect back
}
} else {
// Form was not submitted, so display the form.
}
?>
Edit
I was hoping not to have to do the work for you (since it's best you learn) but perhaps seeing the above code, and the below code you can learn from it that way?
<?php
require_once("nocache.php");
$id = $_POST["id"];
$pword = $_POST["pword"];
if(!empty($_POST)) {
if(!empty($id) || !empty($pword)) {
require_once("dbconn.php");
$sql = "select username, school_type from school_info where username = '$id' and password = '$pword'";
$rs = mysql_query($sql, $dbConn);
if(mysql_num_rows($rs) > 0) {
session_start();
$_SESSION["who"] = $id;
$_SESSION["school_type"] = mysql_result($rs, 0, "school_type");
header("location: EOI_home.php");
}
} else {
header("location: login.php");
}
}
?>
<form method="POST" action="<?php echo $_SERVER["PHP_SELF"];?>" id="login">
ID: <input type="text" name="id" /><br/>
pword: <input type="password" name="pword" /><br/>
<input type="submit" value="log in" />
<input type="reset" />
</form>
The loop is here:
$id = $_POST["id"];
$pword = $_POST["pword"];
if (empty($id) || empty($pword)){
header("location: login.php"); }
If the $_POST values are not set, the redirect happens. Since you are not setting the values before the redirect, it happens again. And again. And again...
To correct this problem, display your form if the $_POST values are not set.

Issue with php mysql login $_POST['username'] = $result['username']

I'm kinda' beginner and I've coded my own PHP login from Zero, but I still got some errors, here's the code:
<?php
include 'connection.php';
$query = " SELECT * FROM admin";
$result = mysql_query($query) or die(mysql_error());
?>
<form action="<?php echo $_SERVER['SELF_PHP']; ?>" method="post">
Username : <input type="text" name="usernameInput" value="" />
Password : <input type="password" name="passwordInput" value="" />
<input type="submit" value="Login" />
</form>
<?php
$username = $_POST['usernameInput'];
$password = $_POST['passwordInput'];
if ($username = $result['username']) {
if ($password = $result['password']){
header('Location: admin.php');
} else {
echo "PASSWORD IS INCORRECT";
}
} else {
echo "USERNAME IS INCORRECT";
}
?>
So if you can fix this or got an easier way from PHP login from please tell me. :)
A few things...
Don't use mysql functions
You need to use == to compare strings, not =
You need to actually fetch the results of your query
include 'connection.php';
$query = " SELECT * FROM admin";
$result = mysql_query($query) or die(mysql_error());
$row = mysql_fetch_row($result); /* add this */
?>
<form action="<?php echo $_SERVER['SELF_PHP']; ?>" method="post">
Username : <input type="text" name="usernameInput" value="" />
Password : <input type="password" name="passwordInput" value="" />
<input type="submit" value="Login" />
</form>
<?php
if(isset($_POST['usernameInput']) && isset($_POST['passwordInput'])){
$username = $_POST['usernameInput'];
$password = $_POST['passwordInput'];
}
else{
echo 'some error ...';
}
if($username == $row ['username'] && $password == $row ['password']){
header('Location: admin.php');
}
else{
echo ' username or password is wrong';
}
?>
I have to point out that you are sending the same form over and over without first checking the post. And when you send the form, you will not be able to send the header to redirect, because html is started and headers are sent already.
Mysql functions are deprecated, please use mysqli interface.
Among other several bugs like assignment = instead of is equal ==
Try it this way:
If no post exists send the form else check and if ok redirect or not ok. resend the form
<?php
if($_POST){
include 'connection.php';
$query = " SELECT * FROM admin";
$r = mysql_query($query) or die(mysql_error());
// get an associated array from query result resource.
$result = mysql_fetch_assoc($r);
$username = $_POST['usernameInput'];
$password = $_POST['passwordInput'];
if ( ($username == $result['username'])
&& ($password == $result['password'])){
header('Location: admin.php');
exit(0);
} else {
echo "PASSWORD IS INCORRECT";
}
}
?>
<form action="<?php echo $_SERVER['SELF_PHP']; ?>" method="post">
Username : <input type="text" name="usernameInput" value="" />
Password : <input type="password" name="passwordInput" value="" />
<input type="submit" value="Login" />
</form>
<?php
?>

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