PHP/MySQL code fail to insert duplicate row - php

Question

I have some PHP code to select data from & insert data into a MYSQL database.
Here's what I'm trying to do:
- receive a barcode serial number from a JSON payload
- connect to the MySQL database
- check a database table (passes) to see if the barcode has been registered
- if so, write this barcode + timestamp into another table (activations). Then return a JSON mssage that it was successful
- if not, return a JSON message that the barcode was not yet registered.
The code below works OK when I check a specific barcode for the first time. But after that it doesn't insert a new entry in the activations table. Instead I get the message 'Activation not recorded' ..
Any idea what I'm doing wrong?
Thanks if you can help!
Andrew
<?php
//Messages will be returned as JSON data
header("Content-type: application/json");
//read the POST payload
$payload = json_decode(file_get_contents('php://input'), true);
//get a database connection
require_once("../class/Database.php");
$db = Database::get();
//check for a valid pass
$barcode = $payload['barcode'];
$statement = $db->prepare("SELECT * FROM passes WHERE barcode = ?");
$statement->execute(array($barcode));
$row = $statement->fetch(PDO::FETCH_ASSOC);
if ($row) {
$statement2 = $db->prepare("INSERT INTO activations(activationDatetime, barcode) VALUES (?,?)");
$statement2->execute(array(date("Y-m-d G:i:s"),$barcode));
if ($statement2->rowCount()==0) {
print json_encode(array("msg"=>"Activation not recorded"));
} else {
print json_encode(array("msg"=>"Pass successfully activated"));
}
} else
{
print json_encode(array("msg"=>"Pass not registered"));
exit();
}
flush();
exit();
?>

Answer 1

I guess if ($statement2->rowCount()==0) { this statement is wrong please check. You can not use "rowCount" there as it is a insert query.
And I think, it is inserted only issue is not showing message properly.

Answer 2

You should print the sql error at the debug stage of your page.
I guess, the barcode field is uniq.