SELECT
tbl_transactions.artid,
tbl_transactions.transcode,
tbl_transactions.startedby,
tbl_user.lastname,
tbl_user.firstname,
sec_to_time(sum(time_to_sec(timediff(dtecompleted,dtestarted)))) as 'Total Time Spent',
(SELECT dtestarted FROM tbl_transactions where transcode = 'sh') as 'shipp date'

FROM
tbl_transactions
inner join tbl_user on (tbl_transactions.startedby = tbl_user.userid)

group by
artid,
transcode


order by
'total time spent' desc