题解 | 二刷

/*delete from
    titles_test
where
    titles_test.id not in (
        select
            t.minid
        from
            (
                select
                    min(id) minid
                from
                    titles_test
                group by
                    emp_no
            ) as t
    )
*/



























/*
#阅读理解，删除重复，对于重复的只保留最小id

delete from titles_test
where id not in
(select 
min(t1.id)
from(
select
* 
from titles_test 
)  as t1
group by t1.emp_no
)
*/

#阅读理解，删除重复，对于重复的只保留最小id
delete from  titles_test
where id not in
(select
min(t1.id)
from (select * from titles_test) as t1
group by t1.emp_no
)