Cannot insert into MySQL database using PDO....No errors - php

Question

I have a problem where I cannot insert anything into a MySQL database using PDO.
I get no errors but whenever I check the database if the row has been inserted, the table is empty.
I know I have a connection to the database as I am able to select but not insert.
Here is my class that entends PDO
class Database extends PDO
{
public function __construct($DB_TYPE, $DB_HOST, $DB_NAME, $DB_USER, $DB_PASS)
{
parent::__construct($DB_TYPE.':host='.$DB_HOST.';dbname='.$DB_NAME, $DB_USER, $DB_PASS);
//parent::setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTIONS);
}
/**
* select
* #param string $sql An SQL string
* #param array $array Paramters to bind
* #param constant $fetchMode A PDO Fetch mode
* #return mixed
*/
public function select($sql, $array = array(), $fetchMode = PDO::FETCH_ASSOC)
{
$sth = $this->prepare($sql);
foreach ($array as $key => $value) {
$sth->bindValue("$key", $value);
}
$sth->execute();
return $sth->fetchAll($fetchMode);
}
/**
* insert
* #param string $table A name of table to insert into
* #param string $data An associative array
*/
public function insert($table, $data)
{
/*ksort($data);
$fieldNames = implode('`, `', array_keys($data));
$fieldValues = ':' . implode(', :', array_keys($data));
$sth = $this->prepare("INSERT INTO $table (`$fieldNames`) VALUES ($fieldValues)");
foreach ($data as $key => $value) {
$sth->bindValue(":$key", $value);
}*/
$sth = $this->prepare("INSERT INTO user (`login`, `password`, `role`) VALUES (:login, :password, :role)");
$sth->bindValue(':login', 'username');
$sth->bindValue(':password', 'password');
$sth->bindValue(':role', 'owner');
$sth->execute();
/*if ($sth->errorCode() != 0) {
$arr = $sth->ErrorInfo();
throw new Exception('SQL failure:'.$arr[0].':'.$arr[1].':'.$arr[2]);
}*/
$sth->debugDumpParams();
}
Here is my table structure (kept it simple for debugging).
CREATE TABLE IF NOT EXISTS `user` (
`userid` int(11) NOT NULL AUTO_INCREMENT,
`login` varchar(25) NOT NULL,
`password` varchar(64) NOT NULL,
`role` enum('default','admin','owner') NOT NULL DEFAULT 'default',
PRIMARY KEY (`userid`)
) ENGINE=InnoDB
EDIT:
I found out where the problem lies. The problem is with the data array. If I use $data['first_name'] when calling the insert() function, it fails but if I replace all those $data[] values with hard codes values, it works so the problem lies with $data[]
I create an array of POST variables
// get all the post data from the registration form
$data = array();
$data['first_name'] = $_POST['first_name'];
$data['last_name'] = $_POST['last_name'];
$data['gender'] = $_POST['gender'];
$data['email'] = $_POST['email'];
$data['interests'] = $_POST['interests'];
$data['username'] = $_POST['username'];
$data['password'] = $_POST['password'];
$data['newsletter'] = $_POST['newsletter'];
$data['terms'] = $_POST['terms'];
$data['captcha'] = $_POST['captcha'];
This gets passed to the create function
public function create($data) {
$this->db->insert('users', array(
'first_name' => $data['first_name'], //this won't work
'first_name' => 'whatever the name is', //this will work
'last_name' => $data['last_name'],
'email' => $data['email'],
'username' => $data['username'],
'password' => $password,
'user_salt' => $user_salt,
'sex' => $data['gender'],
'interests' => $data['interests'],
'signup_date' => date('Y-m-d H:i:s'),
'verification_code' => $code
));
and this is where it gets inserted
public function insert($table, $data)
{
ksort($data);
$fieldNames = implode('`, `', array_keys($data));
$fieldValues = ':' . implode(', :', array_keys($data));
$sth = $this->prepare("INSERT INTO $table (`$fieldNames`) VALUES ($fieldValues)");
foreach ($data as $key => $value) {
$sth->bindValue(":$key", $value);
}
$sth->execute();
}

Answer 1

$fieldValues = implode(':,', array_keys($data));

Answer 2

Try this,
$fieldNames = implode(', ', array_keys($data));
$fieldValues = ':' . implode(', :', array_values($data));
$sth = $this->prepare("INSERT INTO $table ($fieldNames) VALUES ($fieldValues)");