Getting a thrown exception error when trying to update db - php

Question

I created a page where I can edit user information. I am only performing a prepared statement off of one db table called 'users' and in the users db table I have a column called group where I can assign users different permission levels. I am outputting the current data for the user I selected onto this page, so if a user has a group level of 1, in the option field it will show 1. I then have 4 other options which I list the other values at 2, 3, 4, and 5. Whenever I try to submit the form I am getting an exception error from my user class "There was a problem updating!". There update function is below where the exception error is...
public function update($fields = array(), $id = null) {
if(!$id && $this->isLoggedIn()) {
$id = $this->data()->id;
}
if(!$this->_db->update('users', $id, $fields)) {
throw new Exception('There was a problem updating!');
}
}
I believe my prepared statement and form is sound other than possibly the group option area. I want the current group number to be displayed in the option box and if I do not need to update it, I want to be able to click submit and not have any issues and I want to be able to update the group integer.
This is the part I am not sure if it is correct or enabling me to do this..
<div class="field">
<label for="group">Group</label>
<select name="group" required>
<option value=''><?php echo htmlentities($group); ?></option>
<option value="1">Bench</option>
<option value="2">Spectator</option>
<option value="3">Team Member</option>
<option value="4">Commissioner</option>
<option value="5">Creator</option>
</select>
</div>
Here is my prepared statement and form...
<?php
$con = mysqli_connect("localhost","root","","db");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$stmt = $con->prepare("SELECT firstname, lastname, email, username, `group` FROM users WHERE id = ?");
if ( false===$stmt ) {
// Check Errors for prepare
die('prepare() failed: ' . htmlspecialchars($con->error));
}
$stmt->bind_param("i", $_GET['id']);
if ( false===$stmt ) {
// Check errors for binding parameters
die('bind_param() failed: ' . htmlspecialchars($stmt->error));
}
$stmt->execute();
if ( false===$stmt ) {
die('execute() failed: ' . htmlspecialchars($stmt->error));
}
//Check errors for execute
//if(!$stmt->execute()){trigger_error("there was an error....".$con->error, E_USER_WARNING);}
$stmt->bind_result($firstname, $lastname, $email, $username, $group);
$stmt->store_result();
if ($stmt->fetch()) { ?>
<form action="" method="post">
<div class="field">
<label for="firstname">First Name</label>
<input type="text" name="firstname" class="inputbar" value="<?php echo htmlentities($firstname); ?>" required>
</div>
<div class="field">
<label for="lastname">Last Name</label>
<input type="text" name="lastname" class="inputbar" value="<?php echo htmlentities($lastname); ?>" required>
</div>
<div class="field">
<label for="email">Email</label>
<input type="email" class="inputbaremail" name="email" value="<?php echo htmlentities($email); ?>" required>
</div>
<div class="field">
<label for="username">Username</label>
<input type="text" class="inputbar" name="username" value="<?php echo htmlentities($username); ?>" required>
</div>
<div class="field">
<label for="group">Group</label>
<select name="group" required>
<option value=''><?php echo htmlentities($group); ?></option>
<option value="1">Bench</option>
<option value="2">Spectator</option>
<option value="3">Team Member</option>
<option value="4">Commissioner</option>
<option value="5">Creator</option>
<!--<input type="text" class="inputbar" name="group" value="<?php //echo htmlentities($group); ?>" required>-->
</select>
</div>
<input type="hidden" name="token" value="<?php echo Token::generate(); ?>">
<label for="signinButton">
<input type="submit" id="signinButton" value="Update">
</label>
</form>
<?php } else { ?>
User <?php echo htmlentities($_GET['id']); ?> not found.
<?
} ?>
Does anyone see anything that would be preventing this to go through?
UPDATE:
public function update($fields = array(), $id = null) {
if(!$id && $this->isLoggedIn()) {
$id = $this->data()->id;
}
echo $this->_db->update('users', $id, $fields);
}
//if(!$this->_db->update('users', $id, $fields)) {
//throw new Exception('There was a problem updating!');
//}
//if(!$this->_db->update('users', $id, $fields)) {
// throw new Exception('There was a problem updating!')->getMessage();
//}
//}
NEW CODE WITH INSERT PREPARED STATEMENT ADDED. STILL NOT SENDING
if(isset($_POST['submit'])){
$firstname = Input::get('firstname');
$lastname = Input::get('lastname');
$email = Input::get('email');
$username = Input::get('username');
$group = 1;
$con = mysqli_connect("localhost","root","","db");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$stmt2 = $con->prepare("INSERT INTO users (firstname, lastname, email, username, `group`) VALUES (?, ?, ?, ?, ?");
if ( false===$stmt2 ) {
// Check Errors for prepare
die('User Request prepare() failed: ' . htmlspecialchars($con->error));
}
$stmt2->bind_param('sssssi', $firstname, $lastname, $email, $username, $group);
if ( false===$stmt2 ) {
// Check errors for binding parameters
die('User Request bind_param() failed: ' . htmlspecialchars($stmt2->error));
}
$stmt2->execute();
if ( false===$stmt2 ) {
die('User Request execute() failed: ' . htmlspecialchars($stmt2->error));
}
}
//Prepared statement that gets user info
$con = mysqli_connect("localhost","root","","db");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$stmt = $con->prepare("SELECT firstname, lastname, email, username, `group` FROM users WHERE id = ?");
if ( false===$stmt ) {
// Check Errors for prepare
die('prepare() failed: ' . htmlspecialchars($con->error));
}
$stmt->bind_param("i", $_GET['id']);
if ( false===$stmt ) {
// Check errors for binding parameters
die('bind_param() failed: ' . htmlspecialchars($stmt->error));
}
$stmt->execute();
if ( false===$stmt ) {
die('execute() failed: ' . htmlspecialchars($stmt->error));
}
//Check errors for execute
//if(!$stmt->execute()){trigger_error("there was an error....".$con->error, E_USER_WARNING);}
$stmt->bind_result($firstname, $lastname, $email, $username, $group);
$stmt->store_result();
if ($stmt->fetch()) { ?>
Trying to use try/catch...
public function update($fields = array(), $id = null) {
if(!$id && $this->isLoggedIn()) {
$id = $this->data()->id;
}
//echo $this->_db->update('users', $id, $fields);
//if(!$this->_db->update('users', $id, $fields)) {
//throw new Exception('There was a problem updating!');
//}
try {
if(!$this->_db->update('users', $id, $fields)) {
throw new Exception('There was a problem updating!');
}
}
catch(Exception $e) {
echo "An error occurred";
throw $e;
}
finally {
//This overrides the exception as if it were never thrown
return "\nException erased";
}
try {
echo asdf();
}
catch(Exception $e) {
echo "\nResult: " . $e->getMessage();
}
I get this error..
An error occurred
Warning: Cannot modify header information - headers already sent by (output started at /home4/db/public_html/example.com/classes/User.php:46) in /home4/db/public_html/example.com/classes/Redirect.php on line 14
Line 45 of my user class is this..
echo "An error occurred";