Getting the UUID() after INSERT with PHP - php

Question

I am trying to get the UUID that had just been inserted.
This works in phpMyAdmin. But throws an error in PHP.
$insert = $conn->query("
SET #usr_uuid = uuidToBin(UUID());
INSERT INTO `users` (`users`.`usr_uuid`) VALUES ( #usr_uuid );
SELECT HEX(#usr_uuid) AS usr_uuid;
");
However I get this error:
[errno] => 1064
[sqlstate] => 42000
[error] => You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'INSERT INTO `users` (`users`.`usr_uuid`) VALUES ( #u' at line 3
How do I go about fixing this?

Answer 1

You have two options to do it.
The first of all, are using transactions. For example:
$conn->begin_transaction();
$insert = $conn->query("SET #usr_uuid = uuidToBin(UUID());";
$insert = $conn->query("INSERT INTO `users` (`users`.`usr_uuid`) VALUES ( #usr_uuid );";
$insert = $conn->query("SELECT HEX(#usr_uuid) AS usr_uuid;";
$conn->commit();
This option only works if you're using mysqli and innodb storage engine.
Second option, doing two queries:
$insert = $conn->query("INSERT INTO `users` (`users`.`usr_uuid`) VALUES ( uuidToBin(UUID() );";
$insert = $conn->query("SELECT HEX(usr_uuid) AS usr_uuid FROM `users`;";
This option can fall in the problem of having a new insert while you're doing it. But, if the table users have an ID, you can use mysql-insert-id() as suggested by #user3783243