Deleting data in database with dropdown menu in PHP - php

Question

I am struggling with deleting data in my database with my drop-down menu.
My drop-down menu looks like this
<form method="post" action="admin.php">
<h3>Delete a user</h3>
<select name="username">
$sql = mysqli_query($connection, "SELECT username FROM users");
while ($row = $sql->fetch_assoc()){
?>
<option value="username" name="username">
<?php echo $row['username']; ?></option>
<?php } ?>
<input type="submit" name="delete" value="Delete User">
</form>
And this is displaying the users all good like i want it, so here is the php for it
<?php
include('connect.php');
if(isset($_POST['delete'])) {
$username = $_POST['username'];
mysqli_query("DELETE FROM `users` WHERE `username` = '$username' ");
echo "User was deleted!";
}
?>
So when i hit the submit button "Delete User", it looks like i get sent to admin.php and nothing happens.
How can i fix this?
Thanks.

Answer 1

Replace name="username" from <option></option>
Echo value in value of option.
Connection variable missing in admin.php page
Updated Code
<select name="username">
<?php
$sql = mysqli_query($connection, "SELECT username FROM users");
while ($row = $sql->fetch_assoc()){?>
<option value="<?php echo $row['username']; ?>"><?php echo $row['username']; ?></option>
<?php }?>
</select>
admin.php
$stmt = $connection->prepare("DELETE FROM `users` WHERE `username` = ?");
$stmt->bind_param('s', $username);
$stmt->execute();

Answer 2

1.<option value="username" name="username"> Need to be <option value="<?php echo $row['username']; ?>">
2.Connection variable is missing . Need to be:-
mysqli_query($connection,"DELETE FROM `users` WHERE `username` = '$username' ");
Modified code need to be:-
Form code:-
<?php
//comment these two lines when code started working fine
error_reporting(E_ALL);
ini_set('display_errors',1);
include('connect.php');
?>
<form method="post" action="admin.php">
<h3>Delete a user</h3>
<select name="username">
<?php
$sql = mysqli_query($connection, "SELECT username FROM users");
while ($row = mysqli_fetch_assoc($sql)){?>
<option value="<?php echo $row['username']; ?>"><?php echo $row['username']; ?></option>
<?php }?>
</select>
<input type="submit" name="delete" value="Delete User">
</form>
Php code:-
<?php
//comment these two lines when code started working fine
error_reporting(E_ALL);
ini_set('display_errors',1);
include('connect.php');
if(isset($_POST['delete'])) {
$username = $_POST['username'];
if(mysqli_query($connection,"DELETE FROM `users` WHERE `username` = '$username' ")){
echo "User was deleted!";
}
}
?>
Note:- Always do some error-reporting so that you will get error and rectify that.
Your query is vulnerable to SQL INJECTION so read about prepared statements and use them.

Answer 3

Change
<option value="username" name="username">
<?php echo $row['username']; ?></option>
To
<option value="<?php echo $row['username'] ?>" name="username">
<?php echo $row['username']; ?></option>

Answer 4

You are not putting the value in select option that's why nothing happens
Just replace
<option value="username" name="username">
<?php echo $row['username']; ?></option>
<?php } ?>
with
<option value="<?php echo $row['username']; ?>">
<?php echo $row['username']; ?></option>
<?php } ?>
It will work for you.