Question

I have a simple table

CREATE TABLE `keys` (
`IDkey` int NOT NULL auto_increment,
`username` varchar(50) NOT NULL, 
PRIMARY KEY  (`IDkey`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

and give out incrementing integer keys ‘IDkey’ to users as they call in with my webapp. I also store their username in the table.

I have two questions I’m stuck on.

First question: at the moment I am doing the following to give out the key, is there a way to combine this into one query?

INSERT INTO keys VALUES (NULL, '$username');
SELECT IDkey FROM keys WHERE username='$username';

Second Question: the key expires so the same user may return for a new key but this causes a problem because their username is already in the database. Is there a way to write my SELECT query so it returns the most recent record by that user?

Answer 1

If you’re using PDO, check out PDO::lastInsertId().

If you’re using mysqli, check out mysqli::$insert_id.

If you’re using mysql, upgrade your code to use PDO or mysqli. 😉 (But seriously, you can do this with mysql_insert_id()).