mysqli transaction committing only some of queries - php

Question

below is my code. when I use transaction, the transaction is committed but the first query ($receipt_query) is not entered into the DB, the other two are. When running the queries without transaction, all queries are run successfully. So can anyone spot the problem here?!
$mysqli->autocommit(false);
if(!empty($_POST['receipt'])) {
$result = $mysqli->query("insert query 1");
if (!$result) {
$error = 'Some error message';
}
}
if (!empty($_POST['payment'])) {
$result = $mysqli->query("insert query 2");
if (!$result) {
$error = 'Some error message';
}
}
if(empty($error)) {
if($mysqli->query("query 3")) {
$mysqli->commit();
} else {
$mysqli->rollback();
}
} else {
$mysqli->rollback();
}
Doesn't transaction mean "All or None"? so how come the first one doesn't commit even though the whole transaction is committed?

Answer 1

You need to start transaction after autommit.
$mysqli->autocommit(false);
$mysqli->begin_transaction();
An surround the code with try-catch:
try {
// First of all, let's begin a transaction
$mysqli->autocommit(false);
$mysqli->begin_transaction();
// A set of queries
$mysqli->query('first query');
$mysqli->query('second query');
$mysqli->query('third query');
// If we arrive here, it means that no exception was thrown
// i.e. no query has failed, and we can commit the transaction
$mysqli->commit();
} catch (Exception $e) {
// An exception has been thrown
// We must rollback the transaction
$mysqli->rollback();
}