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