Are you tired of checking data in your code before inserting? Well MySQL procedures are here to rescue. This simple procedure shows how you can do that:
CREATE PROCEDURE ` update_insert_user ` ( IN uid2 int )
BEGIN
DECLARE last_login2 DATETIME;
SELECT ` last_login ` INTO last_login2 FROM ` user ` WHERE ` uid ` = uid2 LIMIT 1 ;
IF last_login2 IS NULL THEN
INSERT INTO ` user ` ( ` uid ` , ` last_login ` ) values (uid2, now());
ELSE
UPDATE ` user ` SET ` last_login ` = now() WHERE ` uid ` = uid2 LIMIT 1 ;
END IF ;
END