In the table we have duplicate rows for data to be processed by cron script. Base on latest date(s) from the table values; the script needs to process rows as either add it into another table or delete it.

max-date-rows-with-if.sql

Problem Scenerio:
================
 A) System add new records to be processed for futher into another database table.
 B) System update exiting records to be deleted from the current database table.
 The process A and/or B can be happened any number of times. So system needs to 
 process each record for an entity depending on it is recently added or deleted.
 

SQL:
====
SELECT c.`id`, c.`ct_domain_id`, c.`domain_name`, c.`ct_user_id`, c.`api_status_code`, c.`added_at`, c.`deleted_at`,
IF(`added_at` > IFNULL(`deleted_at`, 0), 'A', 'D') AS `add_or_del`
FROM `qq_domains_sale` AS c
INNER JOIN (
    SELECT MAX(`id`) AS `id` FROM `qq_domains_sale`
    GROUP BY `ct_domain_id`
) AS d
ON c.`id`= d.`id`
WHERE `ct_user_id`=5035
ORDER BY `ct_domain_id` ASC


Thanks:
https://stackoverflow.com/questions/18221999/group-by-having-max-date