1 SQL34

select
 
    device_id, replace(blog_url, "http:/url/", "")
 
from user_submit
select
 
    device_id, substring_index(blog_url, "/", -1) as user_name
 
from user_submit

2 SQL35

select
    substring_index(substring_index(profile, ",", -2), ',', 1) as age, count(device_id) as number
from
    user_submit
group by
    age