Question

Possible Duplicate:
PHP: how to get last inserted ID of a table?

I’m writing a function to add data do a database, but I then want to immediately use that entry in my code.

I know I could query: SELECT id FROM table ORDER BY id DESC

But I wonder if there’s any more direct way of doing it.

Answer 1

That mostly depends on the interface you’re using to access MySQL.

If you’re using PDO (recommended), you’d use PDO::lastInsertId(): http://us.php.net/manual/en/pdo.lastinsertid.php

If you’re using MySQL, you’d use mysql_insert_id() http://php.net/manual/en/function.mysql-insert-id.php

If you’re using MySQLi, you’d use mysqli_insert_id(): http://us.php.net/manual/en/mysqli.insert-id.php

Just simply call whichever function is appropriate right after your INSERT completes.

It’s important to note that you likely do not want to fetch id out of the database using SELECT because if you have multiple writers, you may get the id that some other thread inserted. At best, you’ll operate on the wrong data, and at worst, you could have serious security issues and/or corruption.