can i use aggregation function (LAST) in mysql?? if yes then why give me error for following query::
SELECT `user_id`,last(`value`) FROM `My_TABLE` gro
No, There is nothing called LAST in mysql
See the list of aggregated function
EDIT
You can perform the same something like this
select f.user_id, f.value from ( select MAX(value) as maxval from my_table group by user_id ) as x inner join my_table as f on f.value = x.maxval