Insert stament do not insert values in mysql table using pdo

I am new to pdo, and i wat to create a registration form all the code works including select qury but when i try to insert values to mysql I donot get any error but pdo insert do not insert any values in myaql table and always returns 0 rows insertd
`

<?php
function reg($err)
{
  global $pdo_conn;
  $fname = $err;
  $tab = 'user_details';
  $name = filter_var(strtoupper($_POST['name']), FILTER_SANITIZE_STRING);
  $cc_code = filter_var($_POST['cc_code'], FILTER_SANITIZE_NUMBER_INT);
  $email = filter_var($_POST['email'], FILTER_SANITIZE_EMAIL);
  $key =  password_hash($_POST['key'], PASSWORD_DEFAULT);
  $lvl = 1;
  $date = date("Y-m-d");
  $reg_chk_stmt = 'SELECT * FROM '.$tab. ' WHERE email = :email';
  $reg_chk_qry = $pdo_conn->prepare($reg_chk_stmt);
  $reg_chk_qry->bindParam(':email', $email);
  $reg_chk_qry->execute();
  $reg_chk_rows = $reg_chk_qry->rowCount();
  if ($cc_code != $fname) {
    $err_1 = 'Your firm is not autorized';
  }else {
    //$err_1 = 'your firm is authorized';
    if ($reg_chk_rows != 0) {
      $err_1 = 'email is alredy registerd';
    }else{
      try{
        $reg_ins_stmt = "INSERT INTO " .$tab. " (name, email, pass, firm, lvl, created_on) VALUES (:name, :email, :pass, :firm, :lvl, :created_on)";
        $reg_ins_qry = $pdo_conn->prepare($reg_ins_stmt);
        $reg_ins_qry->bindValue(':name', $name, PDO::PARAM_STR);
        $reg_ins_qry->bindValue(':email', $email, PDO::PARAM_STR);
        $reg_ins_qry->bindValue(':pass', $key, PDO::PARAM_STR);
        $reg_ins_qry->bindValue(':firm', $cc_code, PDO::PARAM_INT);
        $reg_ins_qry->bindValue(':lvl', $lvl, PDO::PARAM_INT);
        $reg_ins_qry->bindValue(':created_on', $created_on, PDO::PARAM_STR);
        $reg_ins_echo = $reg_ins_qry;
        $reg_ins_qry->execute();
        }catch(PDOException $error){
          $err_1 = $error->getMessage();
        }
      $reg_ins_rows = $reg_ins_qry->rowCount();
      if ($reg_ins_rows != 0) {
        $err_1 = $reg_ins_rows;
      }else {
        $err_1 = $reg_ins_rows . $reg_ins_qry;
      }
    }
  }
  $reg_chk_qry = NULL;
  $reg_ins_qry = NULL;
  return $err_1;
}
define('db_host','localhost');
define('db_user','dbuser');
define('db_pass','dbpass');
define('db_name','dbname');
// Establish database connection.
  try
{
$pdo_conn = new PDO("mysql:host=".db_host.";dbname=".db_name,
db_user, db_pass,
array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
//echo "pdo connection works";
}
catch (PDOException $error)
{
exit("Error: could not connect to database");
}
$fname = 21828;
$error = reg($fname);
$header = 'Location: https://xyz.zy/index.php' . '?keyin_err=' . $error;
header($header);
 ?>

`

I tryed to run above code i donot get any error but my code donot insert any valuses to my mysql table