write sql query which returns all post and comments created by user, ordered by date. about apna-reddit HOT 1 CLOSED

select * from (select
'C' as CATEGORY,
comment_id as ID,
comment_content as CONT,
created_at as C_AT,
parent_id as P_ID,
post_id as PO_ID
from comment where user_id='1'
UNION ALL
select
'P' as CATEGORY,
post_id as ID,
content as CONT,
post_created_at as C_AT,
NULL as P_ID,
NULL as PO_ID
from post where user_id='1') as T order by T.C_AT DESC;

from apna-reddit.