Problem converting mysqli to PDO | PHP mySQL - php

Question

I am currently converting my mySQLi PHP code into PDO for better security and I am having some trouble understanding how I can convert the code below and implement it into my new PDO PHP
The code below should take the last inserted ID (the one the PDO is inserting) and set the column idnum equal to the NUM(and the last inserted id).
How can this be converted and added to the PDO?
if (mysqli_query($conn, $sql)) {
$last_id = mysqli_insert_id($conn);
$sql = "UPDATE Equipment SET idnum = CONCAT('NUM', '$last_id') WHERE equipment_id = '$last_id'";
mysqli_query($conn, $sql);
echo "New record created successfully. Last inserted ID is: " . last_id;
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);
I would like to add the code to the following PDO PHP script:
$hostdb = 'localhost';
$namedb = 'dbname';
$userdb = 'userdb';
$passdb = 'passdb';
$charset = 'utf8';
if (isset($_POST['name'], $_POST['place'], $_POST['person'] , $_POST['number'] , $_POST['other_name'])) {
// Connect and create the PDO object
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_EMULATE_PREPARES => false,
];
$conn = new PDO("mysql:host=$hostdb;dbname=$namedb;charset=$charset", $userdb, $passdb, $options);
$stmt = $conn->prepare( ' INSERT INTO `Table1` (name, place, person, number, other_name, progress)
VALUES (:name,:place,:person,:number,:other_name, "Done") ' );
$stmt->execute([
'name' => $_POST['name'],
'place' => $_POST['place'],
'person' => $_POST['person'],
'number' => $_POST['number'],
'other_name' => $_POST['other_name'],
]);
// Shows the number of affected rows
echo 'Affected rows : '. $stmt->rowCount();
}

Answer 1

Like this I guess (if you want them combined):
$hostdb = 'localhost';
$namedb = 'dbname';
$userdb = 'userdb';
$passdb = 'passdb';
$charset = 'utf8';
if (isset($_POST['name'], $_POST['place'], $_POST['person'] , $_POST['number'] , $_POST['other_name'] )) {
// Connect and create the PDO object
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_EMULATE_PREPARES => false,
];
$conn = new PDO("mysql:host=$hostdb;dbname=$namedb;charset=$charset", $userdb, $passdb, $options);
try{
//start a transaction {ACID}
$conn->beginTransaction();
$stmt = $conn->prepare('INSERT INTO `Table1` (`name`, `place`, `person`, `number`, `other_name`, `progress`)
VALUES (:name,:place,:person,:number,:other_name, "Done") ' );
$stmt->execute([
'name' => $_POST['name'],
'place' => $_POST['place'],
'person' => $_POST['person'],
'number' => $_POST['number'],
'other_name' => $_POST['other_name'],
]);
//get the last insert ID
$last_id = $conn->lastInsertId();
$stmt = $conn->prepare('UPDATE `Equipment` SET `idnum` = CONCAT("NUM", :last_id_0) WHERE `equipment_id` = :last_id_1');
//named placeholders must be unique
$stmt->execute([
'last_id_0' => $last_id,
'last_id_1' => $last_id
]);
echo "New record created successfully. Last inserted ID is: " . $last_id;
//commit the changes
$conn->commit();
}catch(PDOException $e){
//roll back the changes on errors
$conn->rollback();
echo $e->getMessage();
}
// Shows the number of affected rows this is pointless (for insert 1 row it's always 1 or an error)
//echo 'Affected rows : '. $stmt->rowCount();
}
Transactions are like changing the DB for pretend (if it's INNODB table), then if there is an error with one of the query both fail.
It's advisable to use them when creating related records that way you don't leave orphan records or rows without the relationship just hanging around.