Sort data (order by) before group by in mysql

Question

I want to group below data from sub_prd_id. but before that i need order data from max created_at.

I wrote query as below.

Answer 1

Query (will always work but is slower than other query):

SQLFIDDLEExample

SELECT t1.*
FROM prd_data t1
WHERE t1.id = (SELECT t2.id
               FROM prd_data t2
               WHERE t2.sub_prd_id= t1.sub_prd_id
               ORDER BY t2.created_at DESC
               LIMIT 1)

Other Query (will work only if sub_prd_id has one MAX value):

SELECT t1.*
FROM prd_data t1
WHERE t1.created_at = (SELECT MAX(t2.created_at)
                       FROM prd_data t2
                       WHERE t2.sub_prd_id= t1.sub_prd_id)

Result:

| ID |      NAME | SUB_PRD_ID |                   CREATED_AT |
--------------------------------------------------------------
|  4 |     Grape |         10 | April, 28 2013 03:11:55+0000 |
|  6 |    Banana |         11 | April, 28 2013 03:23:14+0000 |
|  7 | Pineapple |         12 | April, 28 2013 03:23:44+0000 |