题解 | #删除emp_no重复的记录，只保留最小的id对应的记录。#

sqlite:

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

MySQL中不允许在子查询的同时删除表数据（不能一边查一边把查的表删了）

DELETE FROM titles_test
WHERE id NOT IN(
SELECT * FROM(
SELECT MIN(id)
FROM titles_test
GROUP BY emp_no)a);  -- 把得出的表重命名那就不是原表了