题解 | #删除emp_no重复的记录，只保留最小的id对应的记录。#
删除emp_no重复的记录，只保留最小的id对应的记录。
http://www.nowcoder.com/practice/3d92551a6f6d4f1ebde272d20872cf05
MySQL is not allowed to delete record with selecting action. So the point of this problem is rebuilding a new chart for next step of deleting.
DELETE FROM titles_test
WHERE id NOT IN (
SELECT * FROM(
SELECT MIN(id)
FROM titles_test
GROUP BY emp_no
) as A
)
