How To Group By In Sql By Largest Date (order By A Group By)

I have the following database table Here is my sample data I have for it. What I am trying to figure out how to do is how to write a query to select all apntoken for userid='20'

Solution 1:

My favorite way to construct this SQL is to use a not exists clause like so:

SELECT apntoken,deviceid,created 
FROM `distribution_mobiletokens` as dm
WHERE userid='20'
and not exists (
    select 1 
    from `distribution_mobiletokens`
    where userid = '20'
    and deviceid = dm.deviceid
    and created > dm.created
    )