php - adding 1 to last row of mysql table -

hi i'm trying select last id in table add 1 value. selecting last row find problem i'm having problems +1 think because it's array i'm not sure.

$result = mysql_query("select `id` `users` order `id` desc limit 1"); $row = mysql_fetch_row($result); $pin = $row[0]+1;  echo ($row[0]); //returns id echo ($pin);    // returns null 

any thoughts on great.

try this:

select max(id) + 1 users

but if doing insert, grab mysql_last_insert_id() find out inserted. otherwise have issues concurrency.

your id setup autoincrement correct? should never never never never ever assign primary key yourself. db servers job.