I have little confusion about the Php PDO function: lastInsertID. If I understand correctly, it returns the last auto-incremental id that was inserted in the database.
I usually use this function when I execute a query that inserts a user in my database when I am creating the functionality of registering a user.
My question is that say I have a hundred people registering on my site at one point for example. And may be one user hit the ‘Register’ button a millisecond after another user. Then is there a chance that this function lastInsertId will return the id of another user that register just momentarily earlier?
May be what I am trying to ask is does the server handle one request at a time and go through a php file one at a time?
Please let me know about this.
Perfectly safe. There is no race condition. It only returns the last inserted Id from the pdo object that made the insert.
It is safe – it guarantees to return you a value from the current connection.