delete from titles_test
where id not in
(select * from
(select min(id)
from titles_test
group by emp_no)as min_id) 




# select T.*
# from
# (select
# *,
# rank()over(partition by emp_no order by id) as rp
# from titles_test) as T
# where T.rp = 1



select T.*
from
(select
*,
rank()over(partition by emp_no order by id) as rp
from titles_test) as T
where T.rp = 1