题解 | #删除emp_no重复的记录 易错题#
删除emp_no重复的记录,只保留最小的id对应的记录。
https://www.nowcoder.com/practice/3d92551a6f6d4f1ebde272d20872cf05
delete from titles_test where id not in ( select a.* from (select min(id) from titles_test group by emp_no) a )
不能一边删一边查,需要再套一层